diff --git a/src/main/java/org/jabref/gui/Base.css b/src/main/java/org/jabref/gui/Base.css
index ec78513a06b..ab4097899cc 100644
--- a/src/main/java/org/jabref/gui/Base.css
+++ b/src/main/java/org/jabref/gui/Base.css
@@ -975,3 +975,21 @@ We want to have a look that matches our icons in the tool-bar */
 .color-palette-region .button {
     -fx-border-width: 0px;
 }
+
+
+.warning-icon {
+    -fx-fill: -jr-warn;
+}
+
+.error-icon {
+    -fx-text-fill: -jr-error;
+    -fx-fill: -jr-error;
+}
+
+.tooltip-warning {
+    -fx-background-color: -jr-warn;
+}
+
+.tooltip-error {
+    -fx-background-color: -jr-error;
+}
diff --git a/src/main/java/org/jabref/gui/BasePanel.java b/src/main/java/org/jabref/gui/BasePanel.java
index 777c06eaf6f..ef5e2875994 100644
--- a/src/main/java/org/jabref/gui/BasePanel.java
+++ b/src/main/java/org/jabref/gui/BasePanel.java
@@ -150,7 +150,6 @@ public class BasePanel extends StackPane {
     // Used to track whether the base has changed since last save.
     private BibEntry showing;
 
-    private StringDialog stringDialog;
     private SuggestionProviders suggestionProviders;
 
     @SuppressWarnings({"FieldCanBeLocal", "unused"}) private Subscription dividerPositionSubscription;
@@ -308,17 +307,6 @@ private void setupActions() {
 
         actions.put(Actions.SELECT_ALL, mainTable.getSelectionModel()::selectAll);
 
-        // The action for opening the string editor
-        actions.put(Actions.EDIT_STRINGS, () -> {
-            if (stringDialog == null) {
-                StringDialog form = new StringDialog(frame, BasePanel.this, bibDatabaseContext.getDatabase());
-                form.setVisible(true);
-                stringDialog = form;
-            } else {
-                stringDialog.setVisible(true);
-            }
-        });
-
         // The action for auto-generating keys.
         actions.put(Actions.MAKE_KEY, new GenerateBibtexKeyAction(this, frame.getDialogService()));
 
@@ -374,36 +362,36 @@ private void setupActions() {
 
         actions.put(Actions.MERGE_WITH_FETCHED_ENTRY, new MergeWithFetchedEntryAction(this, frame.getDialogService()));
 
-        actions.put(Actions.REPLACE_ALL, ()-> (new ReplaceStringAction(this)).execute());
+        actions.put(Actions.REPLACE_ALL, () -> (new ReplaceStringAction(this)).execute());
 
         actions.put(new SpecialFieldValueViewModel(SpecialField.RELEVANCE.getValues().get(0)).getCommand(),
-                new SpecialFieldViewModel(SpecialField.RELEVANCE, undoManager).getSpecialFieldAction(SpecialField.RELEVANCE.getValues().get(0), frame));
+                    new SpecialFieldViewModel(SpecialField.RELEVANCE, undoManager).getSpecialFieldAction(SpecialField.RELEVANCE.getValues().get(0), frame));
 
         actions.put(new SpecialFieldValueViewModel(SpecialField.QUALITY.getValues().get(0)).getCommand(),
-                new SpecialFieldViewModel(SpecialField.QUALITY, undoManager).getSpecialFieldAction(SpecialField.QUALITY.getValues().get(0), frame));
+                    new SpecialFieldViewModel(SpecialField.QUALITY, undoManager).getSpecialFieldAction(SpecialField.QUALITY.getValues().get(0), frame));
 
         actions.put(new SpecialFieldValueViewModel(SpecialField.PRINTED.getValues().get(0)).getCommand(),
-                new SpecialFieldViewModel(SpecialField.PRINTED, undoManager).getSpecialFieldAction(SpecialField.PRINTED.getValues().get(0), frame));
+                    new SpecialFieldViewModel(SpecialField.PRINTED, undoManager).getSpecialFieldAction(SpecialField.PRINTED.getValues().get(0), frame));
 
         for (SpecialFieldValue prio : SpecialField.PRIORITY.getValues()) {
             actions.put(new SpecialFieldValueViewModel(prio).getCommand(),
-                    new SpecialFieldViewModel(SpecialField.PRIORITY, undoManager).getSpecialFieldAction(prio, this.frame));
+                        new SpecialFieldViewModel(SpecialField.PRIORITY, undoManager).getSpecialFieldAction(prio, this.frame));
         }
         for (SpecialFieldValue rank : SpecialField.RANKING.getValues()) {
             actions.put(new SpecialFieldValueViewModel(rank).getCommand(),
-                    new SpecialFieldViewModel(SpecialField.RANKING, undoManager).getSpecialFieldAction(rank, this.frame));
+                        new SpecialFieldViewModel(SpecialField.RANKING, undoManager).getSpecialFieldAction(rank, this.frame));
         }
         for (SpecialFieldValue status : SpecialField.READ_STATUS.getValues()) {
             actions.put(new SpecialFieldValueViewModel(status).getCommand(),
-                    new SpecialFieldViewModel(SpecialField.READ_STATUS, undoManager).getSpecialFieldAction(status, this.frame));
+                        new SpecialFieldViewModel(SpecialField.READ_STATUS, undoManager).getSpecialFieldAction(status, this.frame));
         }
 
         actions.put(Actions.TOGGLE_PREVIEW, () -> {
             PreviewPreferences previewPreferences = Globals.prefs.getPreviewPreferences();
             boolean enabled = !previewPreferences.isPreviewPanelEnabled();
             PreviewPreferences newPreviewPreferences = previewPreferences.getBuilder()
-                    .withPreviewPanelEnabled(enabled)
-                    .build();
+                                                                         .withPreviewPanelEnabled(enabled)
+                                                                         .build();
             Globals.prefs.storePreviewPreferences(newPreviewPreferences);
             DefaultTaskExecutor.runInJavaFXThread(() -> setPreviewActiveBasePanels(enabled));
         });
@@ -496,9 +484,9 @@ private void copyTitle() {
         if (!selectedBibEntries.isEmpty()) {
             // Collect all non-null titles.
             List<String> titles = selectedBibEntries.stream()
-                    .filter(bibEntry -> bibEntry.getTitle().isPresent())
-                    .map(bibEntry -> bibEntry.getTitle().get())
-                    .collect(Collectors.toList());
+                                                    .filter(bibEntry -> bibEntry.getTitle().isPresent())
+                                                    .map(bibEntry -> bibEntry.getTitle().get())
+                                                    .collect(Collectors.toList());
 
             if (titles.isEmpty()) {
                 output(Localization.lang("None of the selected entries have titles."));
@@ -530,8 +518,8 @@ private void copyCiteKey() {
 
             String sb = String.join(",", keys);
             String citeCommand = Optional.ofNullable(Globals.prefs.get(JabRefPreferences.CITE_COMMAND))
-                    .filter(cite -> cite.contains("\\")) // must contain \
-                    .orElse("\\cite");
+                                         .filter(cite -> cite.contains("\\")) // must contain \
+                                         .orElse("\\cite");
             Globals.clipboardManager.setContent(citeCommand + "{" + sb + '}');
 
             if (keys.size() == bes.size()) {
@@ -575,7 +563,7 @@ private void copyKeyAndTitle() {
             Layout layout;
             try {
                 layout = new LayoutHelper(sr, Globals.prefs.getLayoutFormatterPreferences(Globals.journalAbbreviationLoader))
-                        .getLayoutFromText();
+                                                                                                                             .getLayoutFromText();
             } catch (IOException e) {
                 LOGGER.info("Could not get layout", e);
                 return;
@@ -719,12 +707,12 @@ private void createMainTable() {
 
         // Update entry editor and preview according to selected entries
         mainTable.addSelectionListener(event -> mainTable.getSelectedEntries()
-                .stream()
-                .findFirst()
-                .ifPresent(entry -> {
-                    preview.setEntry(entry);
-                    entryEditor.setEntry(entry);
-                }));
+                                                         .stream()
+                                                         .findFirst()
+                                                         .ifPresent(entry -> {
+                                                             preview.setEntry(entry);
+                                                             entryEditor.setEntry(entry);
+                                                         }));
 
         // TODO: Register these actions globally
         /*
@@ -814,8 +802,8 @@ public void setupMainPanel() {
         // Saves the divider position as soon as it changes
         // We need to keep a reference to the subscription, otherwise the binding gets garbage collected
         dividerPositionSubscription = EasyBind.monadic(Bindings.valueAt(splitPane.getDividers(), 0))
-                .flatMap(SplitPane.Divider::positionProperty)
-                .subscribe((observable, oldValue, newValue) -> saveDividerLocation(newValue));
+                                              .flatMap(SplitPane.Divider::positionProperty)
+                                              .subscribe((observable, oldValue, newValue) -> saveDividerLocation(newValue));
     }
 
     /**
@@ -846,18 +834,6 @@ private void instantiateSearchAutoCompleter() {
         }
     }
 
-    public void assureStringDialogNotEditing() {
-        if (stringDialog != null) {
-            stringDialog.assureNotEditing();
-        }
-    }
-
-    public void updateStringDialog() {
-        if (stringDialog != null) {
-            stringDialog.refreshTable();
-        }
-    }
-
     private void adjustSplitter() {
         if (mode == BasePanelMode.SHOWING_PREVIEW) {
             splitPane.setDividerPositions(Globals.prefs.getPreviewPreferences().getPreviewPanelDividerPosition().doubleValue());
@@ -945,9 +921,9 @@ public void previousPreviewStyle() {
 
     private void cyclePreview(int newPosition) {
         PreviewPreferences previewPreferences = Globals.prefs.getPreviewPreferences()
-                .getBuilder()
-                .withPreviewCyclePosition(newPosition)
-                .build();
+                                                             .getBuilder()
+                                                             .withPreviewCyclePosition(newPosition)
+                                                             .build();
         Globals.prefs.storePreviewPreferences(previewPreferences);
 
         preview.updateLayout(previewPreferences);
@@ -997,7 +973,7 @@ public void entryEditorClosing(EntryEditor editor) {
      */
     public void ensureNotShowingBottomPanel(BibEntry entry) {
         if (((mode == BasePanelMode.SHOWING_EDITOR) && (entryEditor.getEntry() == entry))
-            || ((mode == BasePanelMode.SHOWING_PREVIEW) && (preview.getEntry() == entry))) {
+        || ((mode == BasePanelMode.SHOWING_PREVIEW) && (preview.getEntry() == entry))) {
             closeBottomPane();
         }
     }
@@ -1054,10 +1030,6 @@ public BibDatabase getDatabase() {
         return bibDatabaseContext.getDatabase();
     }
 
-    public void stringsClosing() {
-        stringDialog = null;
-    }
-
     public void changeTypeOfSelectedEntries(String newType) {
         List<BibEntry> bes = mainTable.getSelectedEntries();
         changeType(bes, newType);
@@ -1105,11 +1077,11 @@ public boolean showDeleteConfirmationDialog(int numberOfEntries) {
             }
 
             return dialogService.showConfirmationDialogWithOptOutAndWait(title,
-                    message,
-                    okButton,
-                    cancelButton,
-                    Localization.lang("Disable this confirmation dialog"),
-                    optOut -> Globals.prefs.putBoolean(JabRefPreferences.CONFIRM_DELETE, !optOut));
+                                                                         message,
+                                                                         okButton,
+                                                                         cancelButton,
+                                                                         Localization.lang("Disable this confirmation dialog"),
+                                                                         optOut -> Globals.prefs.putBoolean(JabRefPreferences.CONFIRM_DELETE, !optOut));
         } else {
             return true;
         }
@@ -1125,16 +1097,15 @@ private void saveDividerLocation(Number position) {
 
         if (mode == BasePanelMode.SHOWING_PREVIEW) {
             PreviewPreferences previewPreferences = Globals.prefs.getPreviewPreferences()
-                    .getBuilder()
-                    .withPreviewPanelDividerPosition(position)
-                    .build();
+                                                                 .getBuilder()
+                                                                 .withPreviewPanelDividerPosition(position)
+                                                                 .build();
             Globals.prefs.storePreviewPreferences(previewPreferences);
         } else if (mode == BasePanelMode.SHOWING_EDITOR) {
             preferences.setEntryEditorDividerPosition(position.doubleValue());
         }
     }
 
-
     /**
      * Perform necessary cleanup when this BasePanel is closed.
      */
@@ -1432,8 +1403,8 @@ public void action() {
 
                     Optional<LinkedFile> linkedFile = files.stream()
                                                            .filter(file -> (FieldName.URL.equalsIgnoreCase(file.getFileType())
-                                                                            || FieldName.PS.equalsIgnoreCase(file.getFileType())
-                                                                            || FieldName.PDF.equalsIgnoreCase(file.getFileType())))
+                                                           || FieldName.PS.equalsIgnoreCase(file.getFileType())
+                                                           || FieldName.PDF.equalsIgnoreCase(file.getFileType())))
                                                            .findFirst();
 
                     if (linkedFile.isPresent()) {
@@ -1441,8 +1412,8 @@ public void action() {
                         try {
 
                             JabRefDesktop.openExternalFileAnyFormat(bibDatabaseContext,
-                                    linkedFile.get().getLink(),
-                                    ExternalFileTypes.getInstance().fromLinkedFile(linkedFile.get(), true));
+                                                                    linkedFile.get().getLink(),
+                                                                    ExternalFileTypes.getInstance().fromLinkedFile(linkedFile.get(), true));
 
                             output(Localization.lang("External viewer called") + '.');
                         } catch (IOException e) {
diff --git a/src/main/java/org/jabref/gui/JabRefFrame.java b/src/main/java/org/jabref/gui/JabRefFrame.java
index 8e4ca768b05..b657ee1e1db 100644
--- a/src/main/java/org/jabref/gui/JabRefFrame.java
+++ b/src/main/java/org/jabref/gui/JabRefFrame.java
@@ -98,6 +98,8 @@
 import org.jabref.gui.keyboard.KeyBinding;
 import org.jabref.gui.menus.FileHistoryMenu;
 import org.jabref.gui.mergeentries.MergeEntriesAction;
+import org.jabref.gui.metadata.BibtexStringEditorAction;
+import org.jabref.gui.metadata.PreambleEditor;
 import org.jabref.gui.push.PushToApplicationButton;
 import org.jabref.gui.push.PushToApplications;
 import org.jabref.gui.search.GlobalSearchBar;
@@ -848,7 +850,8 @@ private MenuBar createMenu() {
 
                 factory.createMenuItem(StandardActions.LIBRARY_PROPERTIES, new DatabasePropertiesAction(this)),
                 factory.createMenuItem(StandardActions.EDIT_PREAMBLE, new PreambleEditor(this)),
-                factory.createMenuItem(StandardActions.EDIT_STRINGS, new OldDatabaseCommandWrapper(Actions.EDIT_STRINGS, this, Globals.stateManager))
+                factory.createMenuItem(StandardActions.EDIT_STRINGS, new BibtexStringEditorAction(this))
+
         );
 
         Menu lookupIdentifiers = factory.createSubMenu(StandardActions.LOOKUP_DOC_IDENTIFIER);
@@ -857,6 +860,7 @@ private MenuBar createMenu() {
             lookupIdentifiers.getItems().add(factory.createMenuItem(identifierAction.getAction(), identifierAction));
         }
 
+        //@formatter:off
         quality.getItems().addAll(
                 factory.createMenuItem(StandardActions.FIND_DUPLICATES, new DuplicateSearch(this, dialogService)),
                 factory.createMenuItem(StandardActions.MERGE_ENTRIES, new MergeEntriesAction(this)),
@@ -971,7 +975,7 @@ private MenuBar createMenu() {
                 ),
                 factory.createMenuItem(StandardActions.ABOUT, new AboutAction())
         );
-
+        //@formatter:on
         MenuBar menu = new MenuBar();
         menu.getStyleClass().add("mainMenu");
         menu.getMenus().addAll(
diff --git a/src/main/java/org/jabref/gui/StringDialog.java b/src/main/java/org/jabref/gui/StringDialog.java
deleted file mode 100644
index 1169b1f7dce..00000000000
--- a/src/main/java/org/jabref/gui/StringDialog.java
+++ /dev/null
@@ -1,455 +0,0 @@
-package org.jabref.gui;
-
-import java.awt.BorderLayout;
-import java.awt.Component;
-import java.awt.Container;
-import java.awt.GridBagConstraints;
-import java.awt.GridBagLayout;
-import java.awt.event.ActionEvent;
-import java.awt.event.WindowAdapter;
-import java.awt.event.WindowEvent;
-import java.io.File;
-import java.util.ArrayList;
-import java.util.Collections;
-import java.util.List;
-
-import javax.swing.AbstractAction;
-import javax.swing.Action;
-import javax.swing.ActionMap;
-import javax.swing.DefaultCellEditor;
-import javax.swing.InputMap;
-import javax.swing.JComponent;
-import javax.swing.JOptionPane;
-import javax.swing.JPanel;
-import javax.swing.JScrollPane;
-import javax.swing.JTable;
-import javax.swing.JTextField;
-import javax.swing.JToolBar;
-import javax.swing.LayoutFocusTraversalPolicy;
-import javax.swing.table.AbstractTableModel;
-import javax.swing.table.TableColumnModel;
-import javax.swing.undo.CompoundEdit;
-
-import org.jabref.Globals;
-import org.jabref.gui.actions.Actions;
-import org.jabref.gui.help.HelpAction;
-import org.jabref.gui.icon.IconTheme;
-import org.jabref.gui.keyboard.KeyBinding;
-import org.jabref.gui.undo.UndoableInsertString;
-import org.jabref.gui.undo.UndoableRemoveString;
-import org.jabref.gui.undo.UndoableStringChange;
-import org.jabref.gui.util.WindowLocation;
-import org.jabref.logic.bibtex.InvalidFieldValueException;
-import org.jabref.logic.bibtex.LatexFieldFormatter;
-import org.jabref.logic.bibtex.comparator.BibtexStringComparator;
-import org.jabref.logic.help.HelpFile;
-import org.jabref.logic.l10n.Localization;
-import org.jabref.model.database.BibDatabase;
-import org.jabref.model.database.KeyCollisionException;
-import org.jabref.model.entry.BibtexString;
-import org.jabref.preferences.JabRefPreferences;
-
-class StringDialog extends JabRefDialog {
-
-    private static final String STRINGS_TITLE = Localization.lang("Strings for library");
-    // A reference to the entry this object works on.
-    private final BibDatabase base;
-    private final BasePanel panel;
-    private final StringTable table;
-    private final HelpAction helpAction;
-
-    private final SaveDatabaseAction saveAction = new SaveDatabaseAction(this);
-
-    // The action concerned with closing the window.
-    private final CloseAction closeAction = new CloseAction();
-    private List<BibtexString> strings;
-
-
-    public StringDialog(JabRefFrame frame, BasePanel panel, BibDatabase base) {
-        super(StringDialog.class);
-        this.panel = panel;
-        this.base = base;
-
-        sortStrings();
-
-        helpAction = new HelpAction(Localization.lang("Help"), HelpFile.STRING_EDITOR);
-
-        addWindowListener(new WindowAdapter() {
-
-            @Override
-            public void windowClosing(WindowEvent e) {
-                closeAction.actionPerformed(null);
-            }
-        });
-
-        // We replace the default FocusTraversalPolicy with a subclass
-        // that only allows the StringTable to gain keyboard focus.
-        setFocusTraversalPolicy(new LayoutFocusTraversalPolicy() {
-
-            @Override
-            protected boolean accept(Component c) {
-                return super.accept(c) && (c instanceof StringTable);
-            }
-        });
-
-        JPanel pan = new JPanel();
-        GridBagLayout gbl = new GridBagLayout();
-        pan.setLayout(gbl);
-        GridBagConstraints con = new GridBagConstraints();
-        con.fill = GridBagConstraints.BOTH;
-        con.weighty = 1;
-        con.weightx = 1;
-
-        StringTableModel stm = new StringTableModel(this, base);
-        table = new StringTable(stm);
-        if (!base.hasNoStrings()) {
-            table.setRowSelectionInterval(0, 0);
-        }
-
-        gbl.setConstraints(table.getPane(), con);
-        pan.add(table.getPane());
-
-        JToolBar tlb = new OSXCompatibleToolbar();
-        InputMap im = tlb.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW);
-        ActionMap am = tlb.getActionMap();
-        im.put(Globals.getKeyPrefs().getKey(KeyBinding.STRING_DIALOG_ADD_STRING), "add");
-        NewStringAction newStringAction = new NewStringAction(this);
-        am.put("add", newStringAction);
-        im.put(Globals.getKeyPrefs().getKey(KeyBinding.STRING_DIALOG_REMOVE_STRING), "remove");
-        RemoveStringAction removeStringAction = new RemoveStringAction(this);
-        am.put("remove", removeStringAction);
-        im.put(Globals.getKeyPrefs().getKey(KeyBinding.SAVE_DATABASE), "save");
-        am.put("save", saveAction);
-        im.put(Globals.getKeyPrefs().getKey(KeyBinding.CLOSE), "close");
-        am.put("close", closeAction);
-        im.put(Globals.getKeyPrefs().getKey(KeyBinding.HELP), "help");
-        am.put("help", helpAction);
-        im.put(Globals.getKeyPrefs().getKey(KeyBinding.UNDO), "undo");
-        UndoAction undoAction = new UndoAction();
-        am.put("undo", undoAction);
-        im.put(Globals.getKeyPrefs().getKey(KeyBinding.REDO), "redo");
-        RedoAction redoAction = new RedoAction();
-        am.put("redo", redoAction);
-
-        tlb.add(newStringAction);
-        tlb.add(removeStringAction);
-        tlb.addSeparator();
-        tlb.add(helpAction);
-        Container conPane = getContentPane();
-        conPane.add(tlb, BorderLayout.NORTH);
-        conPane.add(pan, BorderLayout.CENTER);
-
-        setTitle(STRINGS_TITLE + ": "
-                + panel.getBibDatabaseContext().getDatabaseFile().map(File::getName).orElse(GUIGlobals.UNTITLED_TITLE));
-        WindowLocation pw = new WindowLocation(this, JabRefPreferences.STRINGS_POS_X, JabRefPreferences.STRINGS_POS_Y,
-                JabRefPreferences.STRINGS_SIZE_X, JabRefPreferences.STRINGS_SIZE_Y);
-        pw.displayWindowAtStoredLocation();
-    }
-
-    private static boolean isNumber(String name) {
-        // A pure integer number cannot be used as a string label,
-        // since Bibtex will read it as a number.
-        try {
-            Integer.parseInt(name);
-            return true;
-        } catch (NumberFormatException ex) {
-            return false;
-        }
-    }
-
-    private void sortStrings() {
-        // Rebuild our sorted set of strings:
-        strings = new ArrayList<>();
-        for (String s : base.getStringKeySet()) {
-            strings.add(base.getString(s));
-        }
-        Collections.sort(strings, new BibtexStringComparator(false));
-    }
-
-    public void refreshTable() {
-        sortStrings();
-        table.revalidate();
-        table.clearSelection();
-        table.repaint();
-    }
-
-    public void saveDatabase() {
-        panel.runCommand(Actions.SAVE);
-    }
-
-    public void assureNotEditing() {
-        if (table.isEditing()) {
-            int col = table.getEditingColumn();
-            int row = table.getEditingRow();
-            table.getCellEditor(row, col).stopCellEditing();
-        }
-    }
-
-    static class SaveDatabaseAction extends AbstractAction {
-
-        private final StringDialog parent;
-
-
-        public SaveDatabaseAction(StringDialog parent) {
-            super("Save library", IconTheme.JabRefIcons.SAVE.getIcon());
-            putValue(Action.SHORT_DESCRIPTION, Localization.lang("Save library"));
-            this.parent = parent;
-        }
-
-        @Override
-        public void actionPerformed(ActionEvent e) {
-            parent.saveDatabase();
-        }
-    }
-
-    class StringTable extends JTable {
-
-        private final JScrollPane sp = new JScrollPane(this);
-
-
-        public StringTable(StringTableModel stm) {
-            super(stm);
-            setShowVerticalLines(true);
-            setShowHorizontalLines(true);
-            setColumnSelectionAllowed(true);
-            DefaultCellEditor dce = new DefaultCellEditor(new JTextField());
-            dce.setClickCountToStart(2);
-            setDefaultEditor(String.class, dce);
-            TableColumnModel cm = getColumnModel();
-            cm.getColumn(0).setPreferredWidth(800);
-            cm.getColumn(1).setPreferredWidth(2000);
-            getInputMap().put(Globals.getKeyPrefs().getKey(KeyBinding.CLOSE), "close");
-            getActionMap().put("close", closeAction);
-            getInputMap().put(Globals.getKeyPrefs().getKey(KeyBinding.HELP), "help");
-            getActionMap().put("help", helpAction);
-        }
-
-        public JComponent getPane() {
-            return sp;
-        }
-
-    }
-
-    class StringTableModel extends AbstractTableModel {
-
-        private final BibDatabase tbase;
-        private final StringDialog parent;
-
-
-        public StringTableModel(StringDialog parent, BibDatabase base) {
-            this.parent = parent;
-            this.tbase = base;
-        }
-
-        @Override
-        public Object getValueAt(int row, int col) {
-            return col == 0 ? strings.get(row).getName() : strings.get(row).getContent();
-        }
-
-        @Override
-        public void setValueAt(Object value, int row, int col) {
-            if (col == 0) {
-                // Change name of string.
-                if (!value.equals(strings.get(row).getName())) {
-                    if (tbase.hasStringLabel((String) value)) {
-                        JOptionPane.showMessageDialog(parent, Localization.lang("A string with that label already exists"),
-                                Localization.lang("Label"), JOptionPane.ERROR_MESSAGE);
-                    } else if (((String) value).contains(" ")) {
-                        JOptionPane.showMessageDialog(parent, Localization.lang("The label of the string cannot contain spaces."),
-                                Localization.lang("Label"), JOptionPane.ERROR_MESSAGE);
-                    } else if (((String) value).contains("#")) {
-                        JOptionPane.showMessageDialog(parent, Localization.lang("The label of the string cannot contain the '#' character."),
-                                Localization.lang("Label"), JOptionPane.ERROR_MESSAGE);
-                    } else if (isNumber((String) value)) {
-                        JOptionPane.showMessageDialog(parent, Localization.lang("The label of the string cannot be a number."),
-                                Localization.lang("Label"), JOptionPane.ERROR_MESSAGE);
-                    } else {
-                        // Store undo information.
-                        BibtexString subject = strings.get(row);
-                        panel.getUndoManager().addEdit(
-                                new UndoableStringChange(panel, subject, true, subject.getName(), (String) value));
-                        subject.setName((String) value);
-                        panel.markBaseChanged();
-                        refreshTable();
-                    }
-                }
-            } else {
-                // Change content of string.
-                BibtexString subject = strings.get(row);
-
-                if (!value.equals(subject.getContent())) {
-                    try {
-                        new LatexFieldFormatter(Globals.prefs.getLatexFieldFormatterPreferences())
-                                .format((String) value, "__dummy");
-                    } catch (InvalidFieldValueException ex) {
-                        return;
-                    }
-                    // Store undo information.
-                    panel.getUndoManager().addEdit(
-                            new UndoableStringChange(panel, subject, false, subject.getContent(), (String) value));
-
-                    subject.setContent((String) value);
-                    panel.markBaseChanged();
-                }
-            }
-        }
-
-        @Override
-        public int getColumnCount() {
-            return 2;
-        }
-
-        @Override
-        public int getRowCount() {
-            return strings.size();
-        }
-
-        @Override
-        public String getColumnName(int col) {
-            return col == 0 ? Localization.lang("Label") :
-                Localization.lang("Content");
-        }
-
-        @Override
-        public boolean isCellEditable(int row, int col) {
-            return true;
-        }
-    }
-
-    class CloseAction extends AbstractAction {
-
-        public CloseAction() {
-            super("Close window");
-            putValue(Action.SHORT_DESCRIPTION, Localization.lang("Close dialog"));
-        }
-
-        @Override
-        public void actionPerformed(ActionEvent e) {
-            panel.stringsClosing();
-            dispose();
-        }
-    }
-
-    class NewStringAction extends AbstractAction {
-
-        private final StringDialog parent;
-
-
-        public NewStringAction(StringDialog parent) {
-            super("New string", IconTheme.JabRefIcons.ADD.getIcon());
-            putValue(Action.SHORT_DESCRIPTION, Localization.lang("New string"));
-            this.parent = parent;
-        }
-
-        @Override
-        public void actionPerformed(ActionEvent e) {
-            String name = JOptionPane.showInputDialog(parent, Localization.lang("Please enter the string's label"));
-            if (name == null) {
-                return;
-            }
-            if (isNumber(name)) {
-                JOptionPane.showMessageDialog(parent, Localization.lang("The label of the string cannot be a number."),
-                        Localization.lang("Label"), JOptionPane.ERROR_MESSAGE);
-                return;
-            }
-            if (name.contains("#")) {
-                JOptionPane.showMessageDialog(parent, Localization.lang("The label of the string cannot contain the '#' character."),
-                        Localization.lang("Label"), JOptionPane.ERROR_MESSAGE);
-                return;
-            }
-            if (name.contains(" ")) {
-                JOptionPane.showMessageDialog(parent, Localization.lang("The label of the string cannot contain spaces."),
-                        Localization.lang("Label"), JOptionPane.ERROR_MESSAGE);
-                return;
-            }
-            try {
-                BibtexString bs = new BibtexString(name, "");
-
-                // Store undo information:
-                panel.getUndoManager().addEdit(new UndoableInsertString(panel, panel.getDatabase(), bs));
-
-                base.addString(bs);
-                refreshTable();
-                panel.markBaseChanged();
-            } catch (KeyCollisionException ex) {
-                JOptionPane.showMessageDialog(parent,
-                        Localization.lang("A string with that label already exists"),
-                        Localization.lang("Label"), JOptionPane.ERROR_MESSAGE);
-            }
-        }
-    }
-
-    class RemoveStringAction extends AbstractAction {
-
-        private final StringDialog parent;
-
-
-        public RemoveStringAction(StringDialog parent) {
-            super("Remove selected strings", IconTheme.JabRefIcons.REMOVE.getIcon());
-            putValue(Action.SHORT_DESCRIPTION, Localization.lang("Remove selected strings"));
-            this.parent = parent;
-        }
-
-        @Override
-        public void actionPerformed(ActionEvent e) {
-            int[] sel = table.getSelectedRows();
-            if (sel.length > 0) {
-
-                // Make sure no cell is being edited, as caused by the
-                // keystroke. This makes the content hang on the screen.
-                assureNotEditing();
-
-                String msg = (sel.length > 1 ? Localization.lang("Really delete the %0 selected entries?",
-                        Integer.toString(sel.length)) : Localization.lang("Really delete the selected entry?"));
-                int answer = JOptionPane.showConfirmDialog(parent, msg, Localization.lang("Delete strings"),
-                        JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE);
-                if (answer == JOptionPane.YES_OPTION) {
-                    CompoundEdit ce = new CompoundEdit();
-                    for (int i = sel.length - 1; i >= 0; i--) {
-                        // Delete the strings backwards to avoid moving indexes.
-
-                        BibtexString subject = strings.get(sel[i]);
-
-                        // Store undo information:
-                        ce.addEdit(new UndoableRemoveString(panel, base, subject));
-
-                        base.removeString(subject.getId());
-                    }
-                    ce.end();
-                    panel.getUndoManager().addEdit(ce);
-
-                    refreshTable();
-                    if (!base.hasNoStrings()) {
-                        table.setRowSelectionInterval(0, 0);
-                    }
-                }
-            }
-        }
-    }
-
-    class UndoAction extends AbstractAction {
-
-        public UndoAction() {
-            super("Undo", IconTheme.JabRefIcons.UNDO.getIcon());
-            putValue(Action.SHORT_DESCRIPTION, Localization.lang("Undo"));
-        }
-
-        @Override
-        public void actionPerformed(ActionEvent e) {
-            panel.runCommand(Actions.UNDO);
-        }
-    }
-
-    class RedoAction extends AbstractAction {
-
-        public RedoAction() {
-            super("Redo", IconTheme.JabRefIcons.REDO.getIcon());
-            putValue(Action.SHORT_DESCRIPTION, Localization.lang("Redo"));
-        }
-
-        @Override
-        public void actionPerformed(ActionEvent e) {
-            panel.runCommand(Actions.REDO);
-        }
-    }
-}
diff --git a/src/main/java/org/jabref/gui/collab/StringAddChangeViewModel.java b/src/main/java/org/jabref/gui/collab/StringAddChangeViewModel.java
index 20bf1099ef6..dafb80b125f 100644
--- a/src/main/java/org/jabref/gui/collab/StringAddChangeViewModel.java
+++ b/src/main/java/org/jabref/gui/collab/StringAddChangeViewModel.java
@@ -43,7 +43,7 @@ public boolean makeChange(BasePanel panel, BibDatabase secondary, NamedCompound
 
         try {
             panel.getDatabase().addString(string);
-            undoEdit.addEdit(new UndoableInsertString(panel, panel.getDatabase(), string));
+            undoEdit.addEdit(new UndoableInsertString(panel.getDatabase(), string));
         } catch (KeyCollisionException ex) {
             LOGGER.info("Error: could not add string '" + string.getName() + "': " + ex.getMessage(), ex);
         }
diff --git a/src/main/java/org/jabref/gui/collab/StringChangeViewModel.java b/src/main/java/org/jabref/gui/collab/StringChangeViewModel.java
index 19e68f3a0b9..d44ac099658 100644
--- a/src/main/java/org/jabref/gui/collab/StringChangeViewModel.java
+++ b/src/main/java/org/jabref/gui/collab/StringChangeViewModel.java
@@ -59,14 +59,14 @@ public boolean makeChange(BasePanel panel, BibDatabase secondary, NamedCompound
             BibtexString bs = new BibtexString(label, disk);
             try {
                 panel.getDatabase().addString(bs);
-                undoEdit.addEdit(new UndoableInsertString(panel, panel.getDatabase(), bs));
+                undoEdit.addEdit(new UndoableInsertString(panel.getDatabase(), bs));
             } catch (KeyCollisionException ex) {
                 LOGGER.info("Error: could not add string '" + bs.getName() + "': " + ex.getMessage(), ex);
             }
         } else {
             String mem = string.getContent();
             string.setContent(disk);
-            undoEdit.addEdit(new UndoableStringChange(panel, string, false, mem, disk));
+            undoEdit.addEdit(new UndoableStringChange(string, false, mem, disk));
         }
 
         // Update tmp database:
diff --git a/src/main/java/org/jabref/gui/collab/StringNameChangeViewModel.java b/src/main/java/org/jabref/gui/collab/StringNameChangeViewModel.java
index e9bda7c9f40..b9cd5bb80fe 100644
--- a/src/main/java/org/jabref/gui/collab/StringNameChangeViewModel.java
+++ b/src/main/java/org/jabref/gui/collab/StringNameChangeViewModel.java
@@ -50,13 +50,13 @@ public boolean makeChange(BasePanel panel, BibDatabase secondary, NamedCompound
             BibtexString bs = new BibtexString(disk, content);
             try {
                 panel.getDatabase().addString(bs);
-                undoEdit.addEdit(new UndoableInsertString(panel, panel.getDatabase(), bs));
+                undoEdit.addEdit(new UndoableInsertString(panel.getDatabase(), bs));
             } catch (KeyCollisionException ex) {
                 LOGGER.info("Error: could not add string '" + bs.getName() + "': " + ex.getMessage(), ex);
             }
         } else {
             string.setName(disk);
-            undoEdit.addEdit(new UndoableStringChange(panel, string, true, mem, disk));
+            undoEdit.addEdit(new UndoableStringChange(string, true, mem, disk));
         }
 
         // Update tmp database:
diff --git a/src/main/java/org/jabref/gui/collab/StringRemoveChangeViewModel.java b/src/main/java/org/jabref/gui/collab/StringRemoveChangeViewModel.java
index 4501888a240..eaf66d47304 100644
--- a/src/main/java/org/jabref/gui/collab/StringRemoveChangeViewModel.java
+++ b/src/main/java/org/jabref/gui/collab/StringRemoveChangeViewModel.java
@@ -36,7 +36,7 @@ public boolean makeChange(BasePanel panel, BibDatabase secondary, NamedCompound
 
         try {
             panel.getDatabase().removeString(inMem.getId());
-            undoEdit.addEdit(new UndoableRemoveString(panel, panel.getDatabase(), string));
+            undoEdit.addEdit(new UndoableRemoveString(panel.getDatabase(), string));
         } catch (Exception ex) {
             LOGGER.info("Error: could not add string '" + string.getName() + "': " + ex.getMessage(), ex);
         }
diff --git a/src/main/java/org/jabref/gui/importer/actions/AppendDatabaseAction.java b/src/main/java/org/jabref/gui/importer/actions/AppendDatabaseAction.java
index fbb5d71222e..5231d0edede 100644
--- a/src/main/java/org/jabref/gui/importer/actions/AppendDatabaseAction.java
+++ b/src/main/java/org/jabref/gui/importer/actions/AppendDatabaseAction.java
@@ -45,14 +45,12 @@ public class AppendDatabaseAction implements BaseAction {
 
     private static final Logger LOGGER = LoggerFactory.getLogger(AppendDatabaseAction.class);
 
-    private final JabRefFrame frame;
     private final BasePanel panel;
 
     private final List<Path> filesToOpen = new ArrayList<>();
     private final DialogService dialogService;
 
     public AppendDatabaseAction(JabRefFrame frame, BasePanel panel) {
-        this.frame = frame;
         this.panel = panel;
         dialogService = frame.getDialogService();
     }
@@ -87,7 +85,7 @@ private static void mergeFromBibtex(BasePanel panel, ParserResult parserResult,
             for (BibtexString bs : fromDatabase.getStringValues()) {
                 if (!database.hasStringLabel(bs.getName())) {
                     database.addString(bs);
-                    ce.addEdit(new UndoableInsertString(panel, database, bs));
+                    ce.addEdit(new UndoableInsertString(database, bs));
                 }
             }
         }
diff --git a/src/main/java/org/jabref/gui/metadata/BibtexStringEditorAction.java b/src/main/java/org/jabref/gui/metadata/BibtexStringEditorAction.java
new file mode 100644
index 00000000000..7e37e175319
--- /dev/null
+++ b/src/main/java/org/jabref/gui/metadata/BibtexStringEditorAction.java
@@ -0,0 +1,20 @@
+package org.jabref.gui.metadata;
+
+import org.jabref.gui.JabRefFrame;
+import org.jabref.gui.actions.SimpleCommand;
+import org.jabref.model.database.BibDatabase;
+
+public class BibtexStringEditorAction extends SimpleCommand {
+
+    private final JabRefFrame frame;
+
+    public BibtexStringEditorAction(JabRefFrame jabRefFrame) {
+        this.frame = jabRefFrame;
+    }
+
+    @Override
+    public void execute() {
+        BibDatabase database = frame.getCurrentBasePanel().getDatabase();
+        new BibtexStringEditorDialogView(database).showAndWait();
+    }
+}
diff --git a/src/main/java/org/jabref/gui/metadata/BibtexStringEditorDialog.fxml b/src/main/java/org/jabref/gui/metadata/BibtexStringEditorDialog.fxml
new file mode 100644
index 00000000000..a9ceca60cd6
--- /dev/null
+++ b/src/main/java/org/jabref/gui/metadata/BibtexStringEditorDialog.fxml
@@ -0,0 +1,38 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<?import javafx.scene.control.Button?>
+<?import javafx.scene.control.ButtonType?>
+<?import javafx.scene.control.DialogPane?>
+<?import javafx.scene.control.TableColumn?>
+<?import javafx.scene.control.TableView?>
+<?import javafx.scene.layout.HBox?>
+<?import javafx.scene.layout.VBox?>
+
+<DialogPane minHeight="-Infinity" minWidth="-Infinity" prefHeight="340.0" prefWidth="427.0" xmlns="http://javafx.com/javafx/8.0.171" xmlns:fx="http://javafx.com/fxml/1" fx:controller="org.jabref.gui.metadata.BibtexStringEditorDialogView">
+   <content>
+      <VBox>
+         <children>
+            <TableView fx:id="tblStrings" prefHeight="250.0">
+              <columns>
+                <TableColumn fx:id="colLabel" prefWidth="75.0" text="%Label" />
+                <TableColumn fx:id="colContent" prefWidth="75.0" text="%Content" />
+              </columns>
+               <columnResizePolicy>
+                  <TableView fx:constant="CONSTRAINED_RESIZE_POLICY" />
+               </columnResizePolicy>
+            </TableView>
+            <HBox minWidth="-Infinity" prefHeight="100.0" prefWidth="300.0">
+               <children>
+                <Button fx:id="btnNewString" minWidth="-Infinity" mnemonicParsing="false" onAction="#addString" text="%Add new String" HBox.hgrow="ALWAYS" />
+                  <Button fx:id="btnRemove" mnemonicParsing="false" onAction="#removeString" text="%Remove selected Strings" HBox.hgrow="ALWAYS" />
+                  <Button fx:id="btnHelp" mnemonicParsing="false" onAction="#openHelp" HBox.hgrow="ALWAYS" />
+               </children>
+            </HBox>
+         </children>
+      </VBox>
+   </content>
+   <buttonTypes>
+     <ButtonType fx:constant="CANCEL" />
+     <ButtonType fx:id="saveButton" buttonData="OK_DONE" text="%Save" />
+   </buttonTypes>
+</DialogPane>
diff --git a/src/main/java/org/jabref/gui/metadata/BibtexStringEditorDialogView.java b/src/main/java/org/jabref/gui/metadata/BibtexStringEditorDialogView.java
new file mode 100644
index 00000000000..bdb3f169c00
--- /dev/null
+++ b/src/main/java/org/jabref/gui/metadata/BibtexStringEditorDialogView.java
@@ -0,0 +1,101 @@
+package org.jabref.gui.metadata;
+
+import javafx.event.ActionEvent;
+import javafx.fxml.FXML;
+import javafx.scene.control.Button;
+import javafx.scene.control.ButtonType;
+import javafx.scene.control.TableColumn;
+import javafx.scene.control.TableColumn.CellEditEvent;
+import javafx.scene.control.TableView;
+import javafx.scene.control.Tooltip;
+import javafx.util.converter.DefaultStringConverter;
+
+import org.jabref.gui.icon.IconTheme.JabRefIcons;
+import org.jabref.gui.util.BaseDialog;
+import org.jabref.gui.util.IconValidationDecorator;
+import org.jabref.gui.util.ViewModelTextFieldTableCellVisualizationFactory;
+import org.jabref.logic.l10n.Localization;
+import org.jabref.model.database.BibDatabase;
+
+import com.airhacks.afterburner.views.ViewLoader;
+import de.saxsys.mvvmfx.utils.validation.visualization.ControlsFxVisualizer;
+
+public class BibtexStringEditorDialogView extends BaseDialog<Void> {
+
+    @FXML private Button btnNewString;
+    @FXML private Button btnRemove;
+    @FXML private Button btnHelp;
+    @FXML private ButtonType saveButton;
+
+    @FXML private TableView<BibtexStringViewModel> tblStrings;
+    @FXML private TableColumn<BibtexStringViewModel, String> colLabel;
+    @FXML private TableColumn<BibtexStringViewModel, String> colContent;
+
+    private final ControlsFxVisualizer visualizer = new ControlsFxVisualizer();
+    private final BibtexStringEditorDialogViewModel viewModel;
+
+    public BibtexStringEditorDialogView(BibDatabase database) {
+        viewModel = new BibtexStringEditorDialogViewModel(database);
+
+        ViewLoader.view(this)
+                  .load()
+                  .setAsDialogPane(this);
+
+        Button btnSave = (Button) this.getDialogPane().lookupButton(saveButton);
+
+        btnSave.disableProperty().bind(viewModel.validProperty().not());
+
+        setResultConverter(btn -> {
+            if (saveButton.equals(btn)) {
+                viewModel.save();
+            }
+            return null;
+        });
+
+        setTitle(Localization.lang("Strings for library"));
+    }
+
+    @FXML
+    private void initialize() {
+        visualizer.setDecoration(new IconValidationDecorator());
+
+        btnHelp.setGraphic(JabRefIcons.HELP.getGraphicNode());
+        btnHelp.setTooltip(new Tooltip(Localization.lang("Open Help page")));
+
+        btnNewString.setTooltip(new Tooltip(Localization.lang("New string")));
+        btnRemove.setTooltip(new Tooltip(Localization.lang("Remove selected strings")));
+
+        colLabel.setCellValueFactory(cellData -> cellData.getValue().labelProperty());
+        new ViewModelTextFieldTableCellVisualizationFactory<BibtexStringViewModel, String>().withValidation(BibtexStringViewModel::labelValidation, visualizer).install(colLabel, new DefaultStringConverter());
+
+        colContent.setCellValueFactory(cellData -> cellData.getValue().contentProperty());
+        new ViewModelTextFieldTableCellVisualizationFactory<BibtexStringViewModel, String>().withValidation(BibtexStringViewModel::labelValidation, visualizer).install(colContent, new DefaultStringConverter());
+
+        colLabel.setOnEditCommit((CellEditEvent<BibtexStringViewModel, String> cell) -> {
+            cell.getRowValue().setLabel(cell.getNewValue());
+        });
+        colContent.setOnEditCommit((CellEditEvent<BibtexStringViewModel, String> cell) -> {
+            cell.getRowValue().setContent(cell.getNewValue());
+        });
+
+        tblStrings.itemsProperty().bindBidirectional(viewModel.allStringsProperty());
+        tblStrings.setEditable(true);
+
+        viewModel.seletedItemProperty().bind(tblStrings.getSelectionModel().selectedItemProperty());
+    }
+
+    @FXML
+    private void addString(ActionEvent event) {
+        viewModel.addNewString();
+    }
+
+    @FXML
+    private void openHelp(ActionEvent event) {
+        viewModel.openHelpPage();
+    }
+
+    @FXML
+    private void removeString(ActionEvent event) {
+        viewModel.removeString();
+    }
+}
diff --git a/src/main/java/org/jabref/gui/metadata/BibtexStringEditorDialogViewModel.java b/src/main/java/org/jabref/gui/metadata/BibtexStringEditorDialogViewModel.java
new file mode 100644
index 00000000000..3d4a2789ffa
--- /dev/null
+++ b/src/main/java/org/jabref/gui/metadata/BibtexStringEditorDialogViewModel.java
@@ -0,0 +1,92 @@
+package org.jabref.gui.metadata;
+
+import java.util.List;
+import java.util.Set;
+import java.util.stream.Collectors;
+
+import javafx.beans.property.BooleanProperty;
+import javafx.beans.property.ListProperty;
+import javafx.beans.property.ObjectProperty;
+import javafx.beans.property.SimpleBooleanProperty;
+import javafx.beans.property.SimpleListProperty;
+import javafx.beans.property.SimpleObjectProperty;
+import javafx.beans.value.ObservableValue;
+import javafx.collections.FXCollections;
+import javafx.collections.ObservableList;
+
+import org.jabref.gui.AbstractViewModel;
+import org.jabref.gui.help.HelpAction;
+import org.jabref.logic.bibtex.comparator.BibtexStringComparator;
+import org.jabref.logic.help.HelpFile;
+import org.jabref.model.database.BibDatabase;
+import org.jabref.model.entry.BibtexString;
+
+import org.fxmisc.easybind.EasyBind;
+
+public class BibtexStringEditorDialogViewModel extends AbstractViewModel {
+
+    private final ListProperty<BibtexStringViewModel> allStrings = new SimpleListProperty<>(FXCollections.observableArrayList());
+    private final ObjectProperty<BibtexStringViewModel> selectedItemProperty = new SimpleObjectProperty<>();
+    private final BibDatabase bibDatabase;
+    private final BooleanProperty validProperty = new SimpleBooleanProperty();
+
+    public BibtexStringEditorDialogViewModel(BibDatabase bibDatabase) {
+        this.bibDatabase = bibDatabase;
+        addAllStringsFromDB();
+
+        ObservableList<ObservableValue<Boolean>> allValidProperty = EasyBind.map(allStringsProperty(), BibtexStringViewModel::combinedValidationValidProperty);
+
+        validProperty.bind(EasyBind.combine(allValidProperty, stream -> stream.allMatch(valid -> valid)));
+
+    }
+
+    private void addAllStringsFromDB() {
+
+        Set<BibtexStringViewModel> strings = bibDatabase.getStringValues()
+                                                        .stream()
+                                                        .sorted(new BibtexStringComparator(false))
+                                                        .map(this::convertFromBibTexString)
+                                                        .collect(Collectors.toSet());
+        allStrings.addAll(strings);
+    }
+
+    public ListProperty<BibtexStringViewModel> allStringsProperty() {
+        return this.allStrings;
+    }
+
+    public void addNewString() {
+        allStrings.add(new BibtexStringViewModel("", ""));
+    }
+
+    public void removeString() {
+        allStrings.remove(selectedItemProperty.getValue());
+    }
+
+    private BibtexStringViewModel convertFromBibTexString(BibtexString bibtexString) {
+        return new BibtexStringViewModel(bibtexString.getName(), bibtexString.getContent());
+    }
+
+    public ObjectProperty<BibtexStringViewModel> seletedItemProperty() {
+        return this.selectedItemProperty;
+    }
+
+    public void save() {
+        List<BibtexString> stringsToAdd = allStrings.stream().map(this::fromBibtexStringViewModel).collect(Collectors.toList());
+        bibDatabase.addStrings(stringsToAdd);
+    }
+
+    private BibtexString fromBibtexStringViewModel(BibtexStringViewModel viewModel) {
+        String label = viewModel.labelProperty().getValue();
+        String content = viewModel.contentProperty().getValue();
+        return new BibtexString(label, content);
+
+    }
+
+    public BooleanProperty validProperty() {
+        return validProperty;
+    }
+
+    public void openHelpPage() {
+        HelpAction.openHelpPage(HelpFile.STRING_EDITOR);
+    }
+}
diff --git a/src/main/java/org/jabref/gui/metadata/BibtexStringViewModel.java b/src/main/java/org/jabref/gui/metadata/BibtexStringViewModel.java
new file mode 100644
index 00000000000..c8dd02e52a6
--- /dev/null
+++ b/src/main/java/org/jabref/gui/metadata/BibtexStringViewModel.java
@@ -0,0 +1,90 @@
+package org.jabref.gui.metadata;
+
+import java.util.regex.Pattern;
+
+import javafx.beans.property.ReadOnlyBooleanProperty;
+import javafx.beans.property.SimpleStringProperty;
+import javafx.beans.property.StringProperty;
+
+import org.jabref.logic.l10n.Localization;
+
+import de.saxsys.mvvmfx.utils.validation.CompositeValidator;
+import de.saxsys.mvvmfx.utils.validation.FunctionBasedValidator;
+import de.saxsys.mvvmfx.utils.validation.ValidationMessage;
+import de.saxsys.mvvmfx.utils.validation.ValidationStatus;
+import de.saxsys.mvvmfx.utils.validation.Validator;
+
+public class BibtexStringViewModel {
+
+    private final static Pattern IS_NUMBER = Pattern.compile("-?\\d+(\\.\\d+)?");
+
+    private final StringProperty labelProperty = new SimpleStringProperty();
+    private final StringProperty contentProperty = new SimpleStringProperty();
+
+    private final Validator labelValidator;
+    private final Validator contentValidator;
+    private final CompositeValidator combinedValidator;
+
+    public BibtexStringViewModel(String label, String content) {
+        this.labelProperty.setValue(label);
+        this.contentProperty.setValue(content);
+
+        labelValidator = new FunctionBasedValidator<>(this.labelProperty, BibtexStringViewModel::validateLabel);
+        contentValidator = new FunctionBasedValidator<>(this.contentProperty, BibtexStringViewModel::validateContent);
+        combinedValidator = new CompositeValidator(labelValidator, contentValidator);
+    }
+
+    public ValidationStatus labelValidation() {
+        return labelValidator.getValidationStatus();
+    }
+
+    public ValidationStatus contentValidation() {
+        return contentValidator.getValidationStatus();
+    }
+
+    public ReadOnlyBooleanProperty combinedValidationValidProperty() {
+        return combinedValidator.getValidationStatus().validProperty();
+    }
+
+    public StringProperty labelProperty() {
+        return this.labelProperty;
+    }
+
+    public StringProperty contentProperty() {
+        return this.contentProperty;
+    }
+
+    public void setLabel(String label) {
+        this.labelProperty.setValue(label);
+    }
+
+    public void setContent(String content) {
+        this.contentProperty.setValue(content);
+    }
+
+    private static ValidationMessage validateLabel(String input) {
+        if (input == null) {
+            return ValidationMessage.error("May not be null");
+        } else if (input.trim().isEmpty()) {
+            return ValidationMessage.error(Localization.lang("Please enter the string's label"));
+        } else if (IS_NUMBER.matcher(input).matches()) {
+            return ValidationMessage.error(Localization.lang("The label of the string cannot be a number."));
+        } else if (input.contains("#")) {
+            return ValidationMessage.error(Localization.lang("The label of the string cannot contain the '#' character."));
+        } else if (input.contains(" ")) {
+            return ValidationMessage.error(Localization.lang("The label of the string cannot contain spaces."));
+        } else {
+            return null; // everything is ok
+        }
+    }
+
+    private static ValidationMessage validateContent(String input) {
+        if (input == null) {
+            return ValidationMessage.error(Localization.lang("Must not be empty!"));
+        } else if (input.trim().isEmpty()) {
+            return ValidationMessage.error(Localization.lang("Must not be empty!"));
+        } else {
+            return null; // everything is ok
+        }
+    }
+}
diff --git a/src/main/java/org/jabref/gui/PreambleEditor.java b/src/main/java/org/jabref/gui/metadata/PreambleEditor.java
similarity index 92%
rename from src/main/java/org/jabref/gui/PreambleEditor.java
rename to src/main/java/org/jabref/gui/metadata/PreambleEditor.java
index d28cb2c69c7..757c12aa732 100644
--- a/src/main/java/org/jabref/gui/PreambleEditor.java
+++ b/src/main/java/org/jabref/gui/metadata/PreambleEditor.java
@@ -1,4 +1,4 @@
-package org.jabref.gui;
+package org.jabref.gui.metadata;
 
 import java.util.Optional;
 
@@ -6,12 +6,14 @@
 import javafx.scene.control.DialogPane;
 import javafx.scene.control.TextArea;
 
+import org.jabref.gui.BasePanel;
+import org.jabref.gui.JabRefFrame;
 import org.jabref.gui.actions.SimpleCommand;
 import org.jabref.gui.undo.UndoablePreambleChange;
 import org.jabref.logic.l10n.Localization;
 import org.jabref.model.database.BibDatabase;
 
-class PreambleEditor extends SimpleCommand {
+public class PreambleEditor extends SimpleCommand {
 
     private final TextArea editor = new TextArea();
 
diff --git a/src/main/java/org/jabref/gui/undo/UndoableInsertString.java b/src/main/java/org/jabref/gui/undo/UndoableInsertString.java
index afaece225d8..6485861abbe 100644
--- a/src/main/java/org/jabref/gui/undo/UndoableInsertString.java
+++ b/src/main/java/org/jabref/gui/undo/UndoableInsertString.java
@@ -1,6 +1,5 @@
 package org.jabref.gui.undo;
 
-import org.jabref.gui.BasePanel;
 import org.jabref.logic.l10n.Localization;
 import org.jabref.model.database.BibDatabase;
 import org.jabref.model.database.KeyCollisionException;
@@ -15,14 +14,10 @@ public class UndoableInsertString extends AbstractUndoableJabRefEdit {
     private static final Logger LOGGER = LoggerFactory.getLogger(UndoableInsertString.class);
 
     private final BibDatabase base;
-    private final BasePanel panel;
     private final BibtexString string;
 
-
-    public UndoableInsertString(BasePanel panel, BibDatabase base,
-            BibtexString string) {
+    public UndoableInsertString(BibDatabase base, BibtexString string) {
         this.base = base;
-        this.panel = panel;
         this.string = string;
     }
 
@@ -37,7 +32,6 @@ public void undo() {
 
         // Revert the change.
         base.removeString(string.getId());
-        panel.updateStringDialog();
     }
 
     @Override
@@ -50,8 +44,5 @@ public void redo() {
         } catch (KeyCollisionException ex) {
             LOGGER.warn("Problem to redo `insert entry`", ex);
         }
-
-        panel.updateStringDialog();
     }
-
 }
diff --git a/src/main/java/org/jabref/gui/undo/UndoableRemoveString.java b/src/main/java/org/jabref/gui/undo/UndoableRemoveString.java
index 0f82649f521..2c086ed3cf0 100644
--- a/src/main/java/org/jabref/gui/undo/UndoableRemoveString.java
+++ b/src/main/java/org/jabref/gui/undo/UndoableRemoveString.java
@@ -1,6 +1,5 @@
 package org.jabref.gui.undo;
 
-import org.jabref.gui.BasePanel;
 import org.jabref.logic.l10n.Localization;
 import org.jabref.model.database.BibDatabase;
 import org.jabref.model.database.KeyCollisionException;
@@ -16,13 +15,9 @@ public class UndoableRemoveString extends AbstractUndoableJabRefEdit {
     private final BibDatabase base;
     private final BibtexString string;
 
-    private final BasePanel panel;
-
-    public UndoableRemoveString(BasePanel panel,
-            BibDatabase base, BibtexString string) {
+    public UndoableRemoveString(BibDatabase base, BibtexString string) {
         this.base = base;
         this.string = string;
-        this.panel = panel;
     }
 
     @Override
@@ -33,25 +28,18 @@ public String getPresentationName() {
     @Override
     public void undo() {
         super.undo();
-
         // Revert the change.
         try {
             base.addString(string);
         } catch (KeyCollisionException ex) {
             LOGGER.warn("Problem to undo `remove string`", ex);
         }
-
-        panel.updateStringDialog();
     }
 
     @Override
     public void redo() {
         super.redo();
-
         // Redo the change.
         base.removeString(string.getId());
-
-        panel.updateStringDialog();
     }
-
 }
diff --git a/src/main/java/org/jabref/gui/undo/UndoableStringChange.java b/src/main/java/org/jabref/gui/undo/UndoableStringChange.java
index edcd986833f..9e2c3f0aa49 100644
--- a/src/main/java/org/jabref/gui/undo/UndoableStringChange.java
+++ b/src/main/java/org/jabref/gui/undo/UndoableStringChange.java
@@ -1,6 +1,5 @@
 package org.jabref.gui.undo;
 
-import org.jabref.gui.BasePanel;
 import org.jabref.logic.l10n.Localization;
 import org.jabref.model.entry.BibtexString;
 import org.jabref.model.strings.StringUtil;
@@ -11,24 +10,20 @@ public class UndoableStringChange extends AbstractUndoableJabRefEdit {
     private final String oldValue;
     private final String newValue;
     private final boolean nameChange;
-    private final BasePanel panel;
 
-
-    public UndoableStringChange(BasePanel panel,
-            BibtexString string, boolean nameChange,
-            String oldValue, String newValue) {
+    public UndoableStringChange(BibtexString string, boolean nameChange, String oldValue, String newValue) {
         this.string = string;
         this.oldValue = oldValue;
         this.newValue = newValue;
         this.nameChange = nameChange;
-        this.panel = panel;
     }
 
     @Override
     public String getPresentationName() {
         return (nameChange ? Localization.lang("change string name %0 to %1", StringUtil.boldHTML(oldValue),
-                StringUtil.boldHTML(newValue)) : Localization.lang("change string content %0 to %1",
-                        StringUtil.boldHTML(oldValue), StringUtil.boldHTML(newValue)));
+                                               StringUtil.boldHTML(newValue)) :
+                           Localization.lang("change string content %0 to %1",
+                                             StringUtil.boldHTML(oldValue), StringUtil.boldHTML(newValue)));
     }
 
     @Override
@@ -36,16 +31,11 @@ public void undo() {
         super.undo();
 
         // Revert the change.
-
-        panel.assureStringDialogNotEditing();
-
         if (nameChange) {
             string.setName(oldValue);
         } else {
             string.setContent(oldValue);
         }
-
-        panel.updateStringDialog();
     }
 
     @Override
@@ -53,15 +43,10 @@ public void redo() {
         super.redo();
 
         // Redo the change.
-
-        panel.assureStringDialogNotEditing();
         if (nameChange) {
             string.setName(newValue);
         } else {
             string.setContent(newValue);
         }
-
-        panel.updateStringDialog();
     }
-
 }
diff --git a/src/main/java/org/jabref/gui/util/IconValidationDecorator.java b/src/main/java/org/jabref/gui/util/IconValidationDecorator.java
index 4354f75695b..ada1bf7ab21 100644
--- a/src/main/java/org/jabref/gui/util/IconValidationDecorator.java
+++ b/src/main/java/org/jabref/gui/util/IconValidationDecorator.java
@@ -31,24 +31,28 @@ public IconValidationDecorator(Pos position) {
         this.position = position;
     }
 
+    @Override
     protected Node createErrorNode() {
         return IconTheme.JabRefIcons.ERROR.getGraphicNode();
     }
 
+    @Override
     protected Node createWarningNode() {
         return IconTheme.JabRefIcons.WARNING.getGraphicNode();
     }
 
+    @Override
     public Node createDecorationNode(ValidationMessage message) {
         Node graphic = Severity.ERROR == message.getSeverity() ? createErrorNode() : createWarningNode();
         graphic.getStyleClass().add(Severity.ERROR == message.getSeverity() ? "error-icon" : "warning-icon");
         Label label = new Label();
         label.setGraphic(graphic);
         label.setTooltip(createTooltip(message));
-        label.setAlignment(Pos.CENTER);
+        label.setAlignment(position);
         return label;
     }
 
+    @Override
     protected Tooltip createTooltip(ValidationMessage message) {
         Tooltip tooltip = new Tooltip(message.getText());
         tooltip.getStyleClass().add(Severity.ERROR == message.getSeverity() ? "tooltip-error" : "tooltip-warning");
diff --git a/src/main/java/org/jabref/gui/util/ViewModelTextFieldTableCellVisualizationFactory.java b/src/main/java/org/jabref/gui/util/ViewModelTextFieldTableCellVisualizationFactory.java
new file mode 100644
index 00000000000..fcf93a067b0
--- /dev/null
+++ b/src/main/java/org/jabref/gui/util/ViewModelTextFieldTableCellVisualizationFactory.java
@@ -0,0 +1,54 @@
+package org.jabref.gui.util;
+
+import java.util.function.Function;
+
+import javafx.scene.control.TableCell;
+import javafx.scene.control.TableColumn;
+import javafx.scene.control.cell.TextFieldTableCell;
+import javafx.util.Callback;
+import javafx.util.StringConverter;
+
+import de.saxsys.mvvmfx.utils.validation.ValidationStatus;
+import de.saxsys.mvvmfx.utils.validation.visualization.ControlsFxVisualizer;
+
+public class ViewModelTextFieldTableCellVisualizationFactory<S, T> implements Callback<TableColumn<S, T>, TableCell<S, T>> {
+
+    private ControlsFxVisualizer visualizer;
+    private Function<S, ValidationStatus> validationStatusProperty;
+    private StringConverter<T> stringConverter;
+
+    public ViewModelTextFieldTableCellVisualizationFactory<S, T> withValidation(Function<S, ValidationStatus> validationStatusProperty, ControlsFxVisualizer visualizer) {
+        this.validationStatusProperty = validationStatusProperty;
+        this.visualizer = visualizer;
+        return this;
+    }
+
+    public void install(TableColumn<S, T> column, StringConverter<T> stringConverter) {
+        column.setCellFactory(this);
+        this.stringConverter = stringConverter;
+    }
+
+    @Override
+    public TextFieldTableCell<S, T> call(TableColumn<S, T> param) {
+        return new TextFieldTableCell<S, T>(stringConverter) {
+
+            @Override
+            public void updateItem(T item, boolean empty) {
+                super.updateItem(item, empty);
+
+                if (!empty && (getTableRow() != null)) {
+                    Object rowItem = getTableRow().getItem();
+
+                    if (rowItem != null) {
+                        S vm = (S) rowItem;
+                        if ((visualizer != null) && (validationStatusProperty != null)) {
+                            visualizer.initVisualization(validationStatusProperty.apply(vm), this);
+                        }
+                    }
+                }
+            }
+        };
+
+    }
+
+}
diff --git a/src/main/java/org/jabref/model/database/BibDatabase.java b/src/main/java/org/jabref/model/database/BibDatabase.java
index 40e6abcc0ff..e986136fad2 100644
--- a/src/main/java/org/jabref/model/database/BibDatabase.java
+++ b/src/main/java/org/jabref/model/database/BibDatabase.java
@@ -42,6 +42,7 @@
  * A bibliography database.
  */
 public class BibDatabase {
+
     private static final Logger LOGGER = LoggerFactory.getLogger(BibDatabase.class);
     private static final Pattern RESOLVE_CONTENT_PATTERN = Pattern.compile(".*#[^#]+#.*");
     /**
@@ -131,7 +132,7 @@ public Set<String> getAllVisibleFields() {
             allFields.addAll(e.getFieldNames());
         }
         return allFields.stream().filter(field -> !InternalBibtexFields.isInternalField(field))
-                .collect(Collectors.toSet());
+                        .collect(Collectors.toSet());
     }
 
     /**
@@ -226,7 +227,6 @@ private synchronized void insertEntries(List<BibEntry> newEntries, EntryEventSou
         entries.addAll(newEntries);
     }
 
-
     /**
      * Removes the given entry.
      * The Entry is removed based on the id {@link BibEntry#id}
@@ -287,6 +287,17 @@ public synchronized void addString(BibtexString string) throws KeyCollisionExcep
         bibtexStrings.put(string.getId(), string);
     }
 
+    public void addStrings(Collection<BibtexString> stringsToAdd) {
+        for (BibtexString str : stringsToAdd) {
+            Optional<BibtexString> bibtexString = getStringByName(str.getName());
+            if (bibtexString.isPresent() && !(bibtexString.get().getContent().equals(str.getContent()))) {
+                bibtexString.get().setContent(str.getContent());
+            } else {
+                addString(str);
+            }
+        }
+    }
+
     /**
      * Removes the string with the given id.
      */
@@ -318,15 +329,10 @@ public BibtexString getString(String id) {
     }
 
     /**
-     * Returns the string with the given name.
+     * Returns the string with the given name/label
      */
     public Optional<BibtexString> getStringByName(String name) {
-        for (BibtexString string : getStringValues()) {
-            if (string.getName().equals(name)) {
-                return Optional.of(string);
-            }
-        }
-        return Optional.empty();
+        return getStringValues().stream().filter(string -> string.getName().equals(name)).findFirst();
     }
 
     /**
@@ -356,12 +362,7 @@ public void copyPreamble(BibDatabase database) {
      * Returns true if a string with the given label already exists.
      */
     public synchronized boolean hasStringLabel(String label) {
-        for (BibtexString value : bibtexStrings.values()) {
-            if (value.getName().equals(label)) {
-                return true;
-            }
-        }
-        return false;
+        return bibtexStrings.values().stream().anyMatch(value -> value.getName().equals(label));
     }
 
     /**
@@ -615,5 +616,4 @@ public String generateSharedDatabaseID() {
     public DuplicationChecker getDuplicationChecker() {
         return duplicationChecker;
     }
-
 }
diff --git a/src/main/java/org/jabref/model/entry/BibtexString.java b/src/main/java/org/jabref/model/entry/BibtexString.java
index 52268364cd3..551dc749ad4 100644
--- a/src/main/java/org/jabref/model/entry/BibtexString.java
+++ b/src/main/java/org/jabref/model/entry/BibtexString.java
@@ -7,6 +7,7 @@
  * This class models a BibTex String ("@String")
  */
 public class BibtexString implements Cloneable {
+
     /**
      * Type of a \@String.
      * <p>
@@ -95,6 +96,10 @@ public void setId(String id) {
         hasChanged = true;
     }
 
+    /**
+     * Returns the name/label of the string
+     * @return
+     */
     public String getName() {
         return name;
     }
@@ -176,16 +181,16 @@ public boolean equals(Object o) {
         if (this == o) {
             return true;
         }
-        if (o == null || getClass() != o.getClass()) {
+        if ((o == null) || (getClass() != o.getClass())) {
             return false;
         }
         BibtexString that = (BibtexString) o;
-        return hasChanged == that.hasChanged &&
+        return (Objects.equals(hasChanged,that.hasChanged) &&
                 Objects.equals(name, that.name) &&
                 Objects.equals(content, that.content) &&
-                Objects.equals(id, that.id) &&
-                type == that.type &&
-                Objects.equals(parsedSerialization, that.parsedSerialization);
+                Objects.equals(id, that.id)  &&
+                Objects.equals(type, that.type) &&
+                Objects.equals(parsedSerialization, that.parsedSerialization));
     }
 
     @Override
diff --git a/src/main/resources/l10n/JabRef_en.properties b/src/main/resources/l10n/JabRef_en.properties
index fdeac656d76..634a80d312c 100644
--- a/src/main/resources/l10n/JabRef_en.properties
+++ b/src/main/resources/l10n/JabRef_en.properties
@@ -253,8 +253,6 @@ Delete\ multiple\ entries=Delete multiple entries
 
 Delete\ rows=Delete rows
 
-Delete\ strings=Delete strings
-
 Deleted=Deleted
 
 Permanently\ delete\ local\ file=Permanently delete local file
@@ -1400,7 +1398,6 @@ Toggle\ print\ status=Toggle print status
 Update\ keywords=Update keywords
 Write\ values\ of\ special\ fields\ as\ separate\ fields\ to\ BibTeX=Write values of special fields as separate fields to BibTeX
 You\ have\ changed\ settings\ for\ special\ fields.=You have changed settings for special fields.
-A\ string\ with\ that\ label\ already\ exists=A string with that label already exists
 Connection\ to\ OpenOffice/LibreOffice\ has\ been\ lost.\ Please\ make\ sure\ OpenOffice/LibreOffice\ is\ running,\ and\ try\ to\ reconnect.=Connection to OpenOffice/LibreOffice has been lost. Please make sure OpenOffice/LibreOffice is running, and try to reconnect.
 JabRef\ will\ send\ at\ least\ one\ request\ per\ entry\ to\ a\ publisher.=JabRef will send at least one request per entry to a publisher.
 Correct\ the\ entry,\ and\ reopen\ editor\ to\ display/edit\ source.=Correct the entry, and reopen editor to display/edit source.
@@ -2174,3 +2171,8 @@ File\ extension\:=File extension\:
 Export\ format\ name\:=Export format name\:
 Cleared\ connection\ settings=Cleared connection settings
 Error\ adding\ discovered\ CitationStyles=Error adding discovered CitationStyles
+
+Add\ new\ String=Add new String
+Remove\ selected\ Strings=Remove selected Strings
+Must\ not\ be\ empty\!=Must not be empty\!
+Open\ Help\ page=Open Help page
\ No newline at end of file
diff --git a/src/test/java/org/jabref/model/database/BibDatabaseTest.java b/src/test/java/org/jabref/model/database/BibDatabaseTest.java
index 364c42c54b3..d5632433ff1 100644
--- a/src/test/java/org/jabref/model/database/BibDatabaseTest.java
+++ b/src/test/java/org/jabref/model/database/BibDatabaseTest.java
@@ -122,6 +122,32 @@ public void hasStringLabelFindsString() {
         assertFalse(database.hasStringLabel("VLSI"));
     }
 
+    @Test
+    public void addStringAsCollection() {
+        BibtexString string = new BibtexString("DSP", "Digital Signal Processing");
+        List<BibtexString> strings = Arrays.asList(string);
+        database.addStrings(strings);
+        assertEquals(Optional.of(string), database.getStringByName("DSP"));
+    }
+
+    @Test
+    public void addStringAsCollectionWithUpdatedContent() {
+        BibtexString string = new BibtexString("DSP", "Digital Signal Processing");
+        List<BibtexString> strings = Arrays.asList(string, new BibtexString("DSP", "ABCD"));
+        database.addStrings(strings);
+        assertEquals(Optional.of(string), database.getStringByName("DSP"));
+    }
+
+    @Test
+    public void addStringAsCollectionWithNewContent() {
+        BibtexString string = new BibtexString("DSP", "Digital Signal Processing");
+        BibtexString vlsi = new BibtexString("VLSI", "Very Large Scale Integration");
+        List<BibtexString> strings = Arrays.asList(string, vlsi);
+        database.addStrings(strings);
+        assertEquals(Optional.of(string), database.getStringByName("DSP"));
+        assertEquals(Optional.of(vlsi), database.getStringByName("VLSI"));
+    }
+
     @Test
     public void addSameStringLabelTwiceThrowsKeyCollisionException() {
         BibtexString string = new BibtexString("DSP", "Digital Signal Processing");