diff --git a/static/directives/repo-view/repo-panel-tags.html b/static/directives/repo-view/repo-panel-tags.html
index 4c5ddba14..7b81bc378 100644
--- a/static/directives/repo-view/repo-panel-tags.html
+++ b/static/directives/repo-view/repo-panel-tags.html
@@ -97,7 +97,7 @@
       <td class="hidden-sm hidden-xs"
           ng-class="tablePredicateClass('size', options.predicate, options.reverse)"
           style="width: 80px;">
-        <a ng-click="orderBy('size')">Size</a>
+        <a ng-click="orderBy('size')" data-title="The compressed size of the tag's image" data-container="body" bs-tooltip>Size</a>
       </td>
       <td class="hidden-xs hidden-sm"
           ng-class="tablePredicateClass('image_id', options.predicate, options.reverse)"