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The onupgradeneeded property of the IDBOpenDBRequest interface is the event handler for the upgradeneeded event, triggered when a database of a bigger version number than the existing stored database is loaded.

The event passed to the listener is an IDBVersionChangeEvent.

Inside the event handler function you can include code to upgrade the database structure, as shown in the example below.

Note: This feature is available in Web Workers.


IDBOpenDBRequest.onupgradeneeded = function(event) { ... };


In the following example you can see the onupgradeneeded handler being used to update the database structure if a database with a higher version number is loaded. For a full working example, see our To-do Notifications app (view example live.)

var db;

// Let us open our database
var DBOpenRequest ="toDoList", 4);

// these two event handlers act on the database being opened
// successfully, or not
DBOpenRequest.onerror = function(event) {
  note.innerHTML += '<li>Error loading database.</li>';

DBOpenRequest.onsuccess = function(event) {
  note.innerHTML += '<li>Database initialised.</li>';
  // store the result of opening the database in the db variable.
  // This is used a lot below
  db = DBOpenRequest.result;
  // Run the displayData() function to populate the task list with
  // all the to-do list data already in the IDB

// This event handles the event whereby a new version of the
// database needs to be created Either one has not been created
// before, or a new version number has been submitted via the
// line above
//it is only implemented in recent browsers
DBOpenRequest.onupgradeneeded = function(event) {
  var db =;
  db.onerror = function(event) {
    note.innerHTML += '<li>Error loading database.</li>';

  // Create an objectStore for this database   
  var objectStore = db.createObjectStore("toDoList", { keyPath: "taskTitle" });

  // define what data items the objectStore will contain
  objectStore.createIndex("hours", "hours", { unique: false });
  objectStore.createIndex("minutes", "minutes", { unique: false });
  objectStore.createIndex("day", "day", { unique: false });
  objectStore.createIndex("month", "month", { unique: false });
  objectStore.createIndex("year", "year", { unique: false });
  objectStore.createIndex("notified", "notified", { unique: false });


Specification Status Comment
Indexed Database API
The definition of 'onupgradeneeded' in that specification.
Indexed Database API 2.0
The definition of 'onupgradeneeded' in that specification.
Editor's Draft  

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 23webkit
24 (unprefixed)
(Yes) 10 moz
16.0 (16.0)
10, partial 15 7.1
Available in workers (Yes) ? 37.0 (37.0) ? (Yes) ?
Indexed Database 2.0 58 ? ? ? 45 ?
Feature Android Webview Chrome for Android Edge Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) 22.0 (22.0) 1.0.1 10 22 8
Available in workers (Yes) (Yes) ? 37.0 (37.0) (Yes) ? (Yes) ?
Indexed Database 2.0 58 58 ? ? ? ? 45 ?

See also

Étiquettes et contributeurs liés au document

 Contributeurs à cette page : jpmedley, libbymc, chrisdavidmills, teoli, freaktechnik, fscholz
 Dernière mise à jour par : jpmedley,