.

index.html

@@ -97,6 +97,7 @@
                     <div id="database-buttons">
                         <input type='button' id='btn-delete-answer-databases' value='Delete local answers'>
                         <input type='button' id='btn-delete-cached-questions' value='Delete cached questions'>
+                        <input type='button' id='btn-reset-local' value='Clear all local data'>
                     </div>
                     <div id="local-fileloader">
                         <form id="jsonFile" name="jsonFile" enctype="multipart/form-data" method="post">

js/main.js

@@ -2605,6 +2605,14 @@ $("#btn-delete-cached-questions").click(function(evt) {
         // Do what should be done next...
       });
   } else {}
+$("#btn-reset-local").click(function(evt) {
+  var r = confirm("Clear all local data");
+  if (r == true) {
+  (async () => {
+      const dbs = await window.indexedDB.databases();
+      dbs.forEach(db => { window.indexedDB.deleteDatabase(db.name) });
+  })();
+  } else {}
 });
 
 $("#btn-delete-current").click(function(evt) {