diff --git a/packages/arcgis-rest-geocoder/src/bulk.ts b/packages/arcgis-rest-geocoder/src/bulk.ts
index 72e767cbaa..c6919c50c8 100644
--- a/packages/arcgis-rest-geocoder/src/bulk.ts
+++ b/packages/arcgis-rest-geocoder/src/bulk.ts
@@ -1,7 +1,7 @@
 /* Copyright (c) 2017-2018 Environmental Systems Research Institute, Inc.
  * Apache-2.0 */
 
-import { request } from "@esri/arcgis-rest-request";
+import { request, cleanUrl } from "@esri/arcgis-rest-request";
 
 import { ISpatialReference, IPoint } from "@esri/arcgis-rest-common-types";
 
@@ -86,15 +86,16 @@ export function bulkGeocode(
     );
   }
 
-  return request(options.endpoint + "geocodeAddresses", options).then(
-    response => {
-      const sr = response.spatialReference;
-      response.locations.forEach(function(address: { location: IPoint }) {
-        address.location.spatialReference = sr;
-      });
-      return response;
-    }
-  );
+  return request(
+    `${cleanUrl(options.endpoint)}/geocodeAddresses`,
+    options
+  ).then(response => {
+    const sr = response.spatialReference;
+    response.locations.forEach(function(address: { location: IPoint }) {
+      address.location.spatialReference = sr;
+    });
+    return response;
+  });
 }
 
 export default {
diff --git a/packages/arcgis-rest-geocoder/src/geocode.ts b/packages/arcgis-rest-geocoder/src/geocode.ts
index 6cd75e8e0e..10538ba6e6 100644
--- a/packages/arcgis-rest-geocoder/src/geocode.ts
+++ b/packages/arcgis-rest-geocoder/src/geocode.ts
@@ -4,7 +4,8 @@
 import {
   request,
   IParams,
-  appendCustomParams
+  appendCustomParams,
+  cleanUrl
 } from "@esri/arcgis-rest-request";
 
 import {
@@ -108,21 +109,22 @@ export function geocode(
   }
 
   // add spatialReference property to individual matches
-  return request(options.endpoint + "findAddressCandidates", options).then(
-    response => {
-      const sr = response.spatialReference;
-      response.candidates.forEach(function(candidate: {
-        location: IPoint;
-        extent?: IExtent;
-      }) {
-        candidate.location.spatialReference = sr;
-        if (candidate.extent) {
-          candidate.extent.spatialReference = sr;
-        }
-      });
-      return response;
-    }
-  );
+  return request(
+    `${cleanUrl(options.endpoint)}/findAddressCandidates`,
+    options
+  ).then(response => {
+    const sr = response.spatialReference;
+    response.candidates.forEach(function(candidate: {
+      location: IPoint;
+      extent?: IExtent;
+    }) {
+      candidate.location.spatialReference = sr;
+      if (candidate.extent) {
+        candidate.extent.spatialReference = sr;
+      }
+    });
+    return response;
+  });
 }
 
 export default {
diff --git a/packages/arcgis-rest-geocoder/src/reverse.ts b/packages/arcgis-rest-geocoder/src/reverse.ts
index 0fef4b02cf..fea5554ed0 100644
--- a/packages/arcgis-rest-geocoder/src/reverse.ts
+++ b/packages/arcgis-rest-geocoder/src/reverse.ts
@@ -1,7 +1,7 @@
 /* Copyright (c) 2017-2018 Environmental Systems Research Institute, Inc.
  * Apache-2.0 */
 
-import { request } from "@esri/arcgis-rest-request";
+import { request, cleanUrl } from "@esri/arcgis-rest-request";
 import { IPoint } from "@esri/arcgis-rest-common-types";
 
 import { ILocation, worldGeocoder, IEndpointRequestOptions } from "./helpers";
@@ -75,7 +75,7 @@ export function reverseGeocode(
     options.params.location = coords;
   }
 
-  return request(options.endpoint + "reverseGeocode", options);
+  return request(`${cleanUrl(options.endpoint)}/reverseGeocode`, options);
 }
 
 export default {
diff --git a/packages/arcgis-rest-geocoder/src/suggest.ts b/packages/arcgis-rest-geocoder/src/suggest.ts
index fc6feb5433..fbb63d84a9 100644
--- a/packages/arcgis-rest-geocoder/src/suggest.ts
+++ b/packages/arcgis-rest-geocoder/src/suggest.ts
@@ -1,7 +1,7 @@
 /* Copyright (c) 2017-2018 Environmental Systems Research Institute, Inc.
  * Apache-2.0 */
 
-import { request } from "@esri/arcgis-rest-request";
+import { request, cleanUrl } from "@esri/arcgis-rest-request";
 
 import { worldGeocoder, IEndpointRequestOptions } from "./helpers";
 
@@ -61,7 +61,7 @@ export function suggest(
     options.params.magicKey = requestOptions.magicKey;
   }
 
-  return request(options.endpoint + "suggest", options);
+  return request(`${cleanUrl(options.endpoint)}/suggest`, options);
 }
 
 export default {
diff --git a/packages/arcgis-rest-request/src/index.ts b/packages/arcgis-rest-request/src/index.ts
index c499a2ad3d..336d613097 100644
--- a/packages/arcgis-rest-request/src/index.ts
+++ b/packages/arcgis-rest-request/src/index.ts
@@ -13,3 +13,4 @@ export * from "./utils/process-params";
 export * from "./utils/get-portal";
 export * from "./utils/get-portal-url";
 export * from "./utils/append-custom-params";
+export * from "./utils/clean-url";
diff --git a/packages/arcgis-rest-request/src/utils/clean-url.ts b/packages/arcgis-rest-request/src/utils/clean-url.ts
new file mode 100644
index 0000000000..0bc6fd52de
--- /dev/null
+++ b/packages/arcgis-rest-request/src/utils/clean-url.ts
@@ -0,0 +1,16 @@
+/* Copyright (c) 2018 Environmental Systems Research Institute, Inc.
+ * Apache-2.0 */
+
+/**
+ * Helper method to ensure that user supplied urls don't include whitespace or a trailing slash.
+ */
+export function cleanUrl(url: string) {
+  // trim leading and trailing spaces, but not spaces inside the url
+  url = url.trim();
+
+  // remove the trailing slash to the url if one was included
+  if (url[url.length - 1] === "/") {
+    url = url.slice(0, -1);
+  }
+  return url;
+}
diff --git a/packages/arcgis-rest-request/src/utils/get-portal-url.ts b/packages/arcgis-rest-request/src/utils/get-portal-url.ts
index 755861337c..e4b15ec652 100644
--- a/packages/arcgis-rest-request/src/utils/get-portal-url.ts
+++ b/packages/arcgis-rest-request/src/utils/get-portal-url.ts
@@ -1,7 +1,7 @@
 /* Copyright (c) 2017 Environmental Systems Research Institute, Inc.
  * Apache-2.0 */
 import { IRequestOptions } from "../request";
-
+import { cleanUrl } from "./clean-url";
 /**
  * Helper that returns the appropriate portal url for a given request. `requestOptions.portal` is given
  * precedence over `authentication.portal`. If neither are present, `www.arcgis.com/sharing/rest` is returned.
@@ -12,12 +12,12 @@ import { IRequestOptions } from "../request";
 export function getPortalUrl(requestOptions: IRequestOptions = {}): string {
   // use portal in options if specified
   if (requestOptions.portal) {
-    return requestOptions.portal;
+    return cleanUrl(requestOptions.portal);
   }
 
   // if auth was passed, use that portal
   if (requestOptions.authentication) {
-    return requestOptions.authentication.portal;
+    return cleanUrl(requestOptions.authentication.portal);
   }
 
   // default to arcgis.com
diff --git a/packages/arcgis-rest-request/test/utils/clean-url.test.ts b/packages/arcgis-rest-request/test/utils/clean-url.test.ts
new file mode 100644
index 0000000000..134e172322
--- /dev/null
+++ b/packages/arcgis-rest-request/test/utils/clean-url.test.ts
@@ -0,0 +1,47 @@
+/* Copyright (c) 2018 Environmental Systems Research Institute, Inc.
+ * Apache-2.0 */
+
+import { cleanUrl } from "../../src/utils/clean-url";
+
+const validUrl =
+  "https://server.com/arcgis/rest/services/Custom Space/MapServer";
+
+describe("cleanUrl", () => {
+  it("should not mangle a valid url", () => {
+    expect(
+      cleanUrl(
+        "https://server.com/arcgis/rest/services/Custom Space/MapServer/"
+      )
+    ).toEqual(validUrl);
+  });
+
+  it("should add a trailing slash", () => {
+    expect(
+      cleanUrl("https://server.com/arcgis/rest/services/Custom Space/MapServer")
+    ).toEqual(validUrl);
+  });
+
+  it("should remove leading whitespace", () => {
+    expect(
+      cleanUrl(
+        "  https://server.com/arcgis/rest/services/Custom Space/MapServer/"
+      )
+    ).toEqual(validUrl);
+  });
+
+  it("should remove trailing whitespace", () => {
+    expect(
+      cleanUrl(
+        "https://server.com/arcgis/rest/services/Custom Space/MapServer/   "
+      )
+    ).toEqual(validUrl);
+  });
+
+  it("should do it all at once", () => {
+    expect(
+      cleanUrl(
+        "  https://server.com/arcgis/rest/services/Custom Space/MapServer       "
+      )
+    ).toEqual(validUrl);
+  });
+});