diff --git a/www/assert/index.html b/www/assert/index.html
index f4867629f..eb0bd659f 100644
--- a/www/assert/index.html
+++ b/www/assert/index.html
@@ -19,6 +19,11 @@
         .error {
             border: 1px solid red;
         }
+        .thumb {
+            max-height: 150px;
+            width: auto;
+            border: 3px solid black;
+        }
     </style>
 
 </head>
@@ -36,6 +41,7 @@
 <!-- -->
 <div id="quot"><p>"pewpewpew"</p></div>
 
+
 <hr>
 
 <h2>Test 2</h2>
@@ -45,3 +51,6 @@
 <div id="widget"><div data-cke-widget-id="0" tabindex="-1" data-cke-widget-wrapper="1" data-cke-filter="off" class="cke_widget_wrapper cke_widget_block" data-cke-display-name="macro:velocity" contenteditable="false"><div class="macro cke_widget_element" data-macro="startmacro:velocity|-||-|Here is a macro" data-cke-widget-data="%7B%22classes%22%3A%7B%22macro%22%3A1%7D%7D" data-cke-widget-upcasted="1" data-cke-widget-keep-attr="0" data-widget="xwiki-macro"><p>Here is a macro</p></div><span style='background: rgba(220, 220, 220, 0.5) url("/customize/cryptofist_small.png") repeat scroll 0% 0%; top: -15px; left: 0px; display: block;' class="cke_reset cke_widget_drag_handler_container"><img title="Click and drag to move" src="data:image/gif;base64,R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw==" data-cke-widget-drag-handler="1" class="cke_reset cke_widget_drag_handler" height="15" width="15"></span></div></div>
 
 <hr>
+
+<img id="thumb-orig" src="/customize/alt-favicon.png" />
+
diff --git a/www/assert/main.js b/www/assert/main.js
index 7124f58d9..4a2ccc3d8 100644
--- a/www/assert/main.js
+++ b/www/assert/main.js
@@ -5,8 +5,9 @@ define([
     'json.sortify',
     '/common/cryptpad-common.js',
     '/drive/tests.js',
-    '/common/test.js'
-], function ($, Hyperjson, TextPatcher, Sortify, Cryptpad, Drive, Test) {
+    '/common/test.js',
+    '/common/common-thumbnail.js',
+], function ($, Hyperjson, TextPatcher, Sortify, Cryptpad, Drive, Test, Thumb) {
     window.Hyperjson = Hyperjson;
     window.TextPatcher = TextPatcher;
     window.Sortify = Sortify;
@@ -207,6 +208,31 @@ define([
         return cb(true);
     }, "version 2 hash failed to parse correctly");
 
+    assert(function (cb) {
+        var getBlob = function (url, cb) {
+            var xhr = new XMLHttpRequest();
+            xhr.open("GET", url, true);
+            xhr.responseType = "blob";
+            xhr.onload = function () {
+                cb(void 0, this.response);
+            };
+            xhr.send();
+        };
+
+        var $img = $('img#thumb-orig');
+        getBlob($img.attr('src'), function (e, blob) {
+            console.log(e, blob);
+            Thumb.fromImageBlob(blob, function (e, thumb) {
+                console.log(thumb);
+                var th = new Image();
+                th.src = URL.createObjectURL(thumb);
+                th.onload = function () {
+                    $(document.body).append($(th).addClass('thumb'));
+                    cb(th.width === 100 && th.height === 100);
+                };
+            });
+        });
+    });
 
     Drive.test(assert);