diff --git a/app/assets/stylesheets/scss/_download.scss b/app/assets/stylesheets/scss/_download.scss
index b45147e85..ffc8f8a9c 100644
--- a/app/assets/stylesheets/scss/_download.scss
+++ b/app/assets/stylesheets/scss/_download.scss
@@ -3,6 +3,10 @@
 .o-download {
 	margin-top: $spacing-sm;
 	text-align: right;
+
+	#download-select-label {
+		font-size: .98rem; margin-left: 1ch;
+	}
 }
 
 *[class*="o-download__"] {
@@ -10,7 +14,6 @@
 	display: inline-flex;
 	align-items: center;
 	gap: 1ch;
-	width: 220px;
 	padding: 6px 10px;
 	border: none;
 	background-color: $lighter-blue;
@@ -30,8 +33,12 @@
 	}
 
 	&:hover {
-    opacity: 0.85;
-  }
+		opacity: 0.85;
+	}
+
+	&:disabled, &.disabled {
+		background-color: $lighter-gray;
+	}
 }
 
 .o-download__files #download_icon::before {
@@ -52,9 +59,9 @@
 			content: '\f1ce';
 			color: $medium-blue;
 			position: absolute;
-		  top: -3px; left: 0;
-		  -webkit-animation: fa-spin 2s infinite linear;
-  		animation: fa-spin 2s infinite linear;
+			top: -3px; left: 0;
+			-webkit-animation: fa-spin 2s infinite linear;
+			animation: fa-spin 2s infinite linear;
 		}	
 	}
 }
diff --git a/app/assets/stylesheets/scss/_file-group.scss b/app/assets/stylesheets/scss/_file-group.scss
index 960845e35..9b067e5fa 100644
--- a/app/assets/stylesheets/scss/_file-group.scss
+++ b/app/assets/stylesheets/scss/_file-group.scss
@@ -11,7 +11,6 @@
     }
 
   }
-
 }
 
 .c-file-group__summary {
@@ -64,6 +63,27 @@
     margin-left: 1ch;
   }
 
+  #download-select {
+    margin-left: .75ch;
+    margin-right: .5ch;
+  }
+}
+
+.select-file-download, #download-select {
+  display: none;
+}
+.large_download {
+  #download-select {
+    display: inline-block;
+  }
+  .select-file-download {
+    display: inline-block;
+    margin-left: .5ch;
+  }
+  span.select-file-download {
+    display: inline-block;
+    width: 1.4ch;
+  }
 }
 
 .c-file-group__list {
@@ -88,8 +108,8 @@
       max-width: 100%;
     }
 
-    span {
-      flex-basis: calc(100% - 100px);
+    & > span {
+      flex-basis: calc(100% - 106px);
       display: flex;
       justify-content: space-between;
       flex-wrap: wrap;
diff --git a/app/views/stash_engine/downloads/_download.html.erb b/app/views/stash_engine/downloads/_download.html.erb
index 43d17db48..9b39fa3bd 100644
--- a/app/views/stash_engine/downloads/_download.html.erb
+++ b/app/views/stash_engine/downloads/_download.html.erb
@@ -3,26 +3,52 @@
 <script type="text/javascript" src="https://16077a4ae659.us-west-2.captcha-sdk.awswaf.com/16077a4ae659/jsapi.js" defer></script>
 <% end %>
 <% worker_scope = request.fullpath.split('/').first(3).join('/') + '/' %>
-<% if resource.total_file_size < APP_CONFIG.maximums.zip_size %>
-  <div class="o-download">
-    <%= form_with url: "#{worker_scope}downloadZip/#{"doi_#{dataset_identifier.identifier}__v#{minimal_date(resource.publication_date.present? && resource.publication_date < Time.now.utc ? resource.publication_date : resource.updated_at)}".gsub(/\.|:|\//, '_')}.zip", method: :post, name: 'download', id: 'zip_download', remote: true do |form| %>
-        <div id="file_downloads"></div>
-        <button type="button" class="o-download__files js-download" id="download_zip_button"><span id="download_icon"></span>Download full dataset</button>
-    <% end %>
-    <div class="screen-reader-only" id="accessible-dl-msg" aria-live="assertive"></div>
-  </div>
-  <% content_for :doc_end do %>
-  <% params = {resource_id: @resource.id} %>
-  <% params[:share] = share if share.present? %>
-  <script type="text/javascript" async>
-    const dlbutton = document.getElementById('download_zip_button');
-    if ("serviceWorker" in navigator) {
-      const zip_url = '<%= stash_url_helpers.zip_assembly_info_path(params)%>';    
-      const scope = '<%= worker_scope %>';
-      <%= render partial: 'stash_engine/downloads/download_zip', formats: :js %>
-    } else {
-      dlbutton.hidden = true;
+<div class="o-download">
+  <%= form_with url: "#{worker_scope}downloadZip/#{"doi_#{dataset_identifier.identifier}__v#{minimal_date(resource.publication_date.present? && resource.publication_date < Time.now.utc ? resource.publication_date : resource.updated_at)}".gsub(/\.|:|\//, '_')}.zip", method: :post, name: 'download', id: 'zip_download', remote: true do |form| %>
+      <div id="file_downloads"></div>
+      <% if resource.total_file_size > APP_CONFIG.maximums.zip_size %>
+        <p id="download-select-label">Select up to <%= filesize(APP_CONFIG.maximums.zip_size) %> of files for download</p>
+      <% end %>
+      <button type="button" class="o-download__files js-download" id="download_zip_button" <% if resource.total_file_size > APP_CONFIG.maximums.zip_size %>disabled<%end%>>
+        <span id="download_icon"></span>
+        <% if resource.total_file_size < APP_CONFIG.maximums.zip_size %>Download full dataset<% else %>Download selected files<%end%>
+      </button>
+  <% end %>
+  <div class="screen-reader-only" id="accessible-dl-msg" aria-live="assertive"></div>
+</div>
+<% content_for :doc_end do %>
+<% params = {resource_id: @resource.id} %>
+<% params[:share] = share if share.present? %>
+<script type="text/javascript" async>
+  <% if resource.total_file_size > APP_CONFIG.maximums.zip_size %>
+    const maxSize = <%= APP_CONFIG.maximums.zip_size %>
+    const selectForm = document.getElementById('download-select-form')
+    const selectDownloads = () => {
+      const els = Array.from(selectForm.elements)
+      if (els.some(i => i.checked)) {
+        document.getElementById('download_zip_button').disabled = false
+      } else {
+        document.getElementById('download_zip_button').disabled = true
+      }
+      const selectedSize = els.reduce((size, el) => {
+        if (el.checked) size += Number(el.dataset.size)
+        return size
+      }, 0)
+      els.forEach(el => {
+        el.disabled = !el.checked && Number(el.dataset.size) + selectedSize > maxSize
+      })
     }
-  </script>
+    selectDownloads()
+    selectForm.addEventListener('change', selectDownloads)
   <% end %>
+  const dlbutton = document.getElementById('download_zip_button');
+  if ("serviceWorker" in navigator) {
+    const zip_url = '<%= stash_url_helpers.zip_assembly_info_path(params)%>';    
+    const scope = '<%= worker_scope %>';
+    <%= render partial: 'stash_engine/downloads/download_zip', formats: :js %>
+  } else {
+    dlbutton.hidden = true;
+    document.getElementById('download_resource').classList.remove('large_download');
+  }
+</script>
 <% end %>
\ No newline at end of file
diff --git a/app/views/stash_engine/downloads/_download_zip.js.erb b/app/views/stash_engine/downloads/_download_zip.js.erb
index 0b699b42a..533217aca 100644
--- a/app/views/stash_engine/downloads/_download_zip.js.erb
+++ b/app/views/stash_engine/downloads/_download_zip.js.erb
@@ -9,13 +9,16 @@ navigator.serviceWorker.ready.then(worker => {
   worker.active.postMessage({type: 'PORT_INITIALIZATION', url: form.action}, [messageChannel.port2]); 
 });
 const insertFiles = async (files) => {
+  const selectForm = document.getElementById('download-select-form').elements
   for (const f of files) {
-    for (const k of Object.keys(f)) {
-      const i = document.createElement('input');
-      i.setAttribute('type', 'hidden');
-      i.setAttribute('name', k);
-      i.setAttribute('value', f[k]);
-      inputs.appendChild(i);
+    if (selectForm[f.filename].checked) {
+      for (const k of Object.keys(f)) {
+        const i = document.createElement('input');
+        i.setAttribute('type', 'hidden');
+        i.setAttribute('name', k);
+        i.setAttribute('value', f[k]);
+        inputs.appendChild(i);
+      }
     }
   }
   return true;
diff --git a/app/views/stash_engine/landing/_files.html.erb b/app/views/stash_engine/landing/_files.html.erb
index 4ae86cdd4..ca88655d9 100644
--- a/app/views/stash_engine/landing/_files.html.erb
+++ b/app/views/stash_engine/landing/_files.html.erb
@@ -14,14 +14,15 @@
 <div class="data_files_section">
   <h2>Data files</h2>
   <div>
-  <% if resources.count.positive? %>      
+  <% if resources.count.positive? %>
     <!-- list individual files -->
     <% resources.each do |res| %>
-      <details class="c-file-group" role="group"<%if res.id === resources.last.id && (res.current_file_uploads.count < 10 || res.total_file_size > APP_CONFIG.maximums.zip_size) %> open<%end%>>
+      <details <% if dl_resource == resource %>id="download_resource"<% end %> class="c-file-group<% if dl_resource == resource && resource.total_file_size > APP_CONFIG.maximums.zip_size %> large_download<% end %>" role="group"<%if res.id === resources.last.id && (res.current_file_uploads.count < 10 || res.total_file_size > APP_CONFIG.maximums.zip_size) %> open<%end%>>
         <summary role="button" class="o-showhide__summary c-file-group__summary">
           <span><%= formatted_date(res.publication_date.present? && res.publication_date < Time.now.utc ? res.publication_date : res.updated_at) %> version files</span>
-          <span><%= filesize(res.total_file_size) %></span>
+          <span><%= filesize(res.total_file_size) %><i id="download-select" class="fas fa-download" title="Select up to <%= filesize(APP_CONFIG.maximums.zip_size) %> of files for download"></i></span>
         </summary>
+        <% if dl_resource == resource %><form id="download-select-form" aria-labelledby="download-select-label"><% end %>
         <ul class="c-file-group__list">
           <% res.current_file_uploads.each do |fu| %>
           <% params = {file_id: fu.id} %>
@@ -34,10 +35,20 @@
                 <i class="fa fa-spin fa-spinner" aria-hidden="true" style="color: #888"></i>
               </div>
               </span>
-              <%= filesize(fu.upload_file_size) %>
+              <div>
+                <%= filesize(fu.upload_file_size) %>
+                <% if dl_resource == resource %>
+                <% if fu.upload_file_size < APP_CONFIG.maximums.zip_size %>
+                  <input class="select-file-download" data-size="<%= fu.upload_file_size %>" type="checkbox" name="<%= fu.upload_file_name%>" <%if resource.total_file_size < APP_CONFIG.maximums.zip_size %>checked<% end %> aria-label="Select <%= fu.upload_file_name%> for download">
+                <% else %>
+                  <span class="select-file-download" title="Too big for zip download" aria-label="Too big for zip download"></span>
+                <% end %>
+                <% end %>
+              </div>
             </li>
           <% end %>
         </ul>
+        <% if dl_resource == resource %></form><% end %>
       </details>
     <% end %>
     <div id="file_preview_box"></div>