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;

// Request version 3 of the database.
var request ="library", 3);

// 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.
request.onupgradeneeded = function(event) {
  db = request.result;
  db.onerror = function(errorEvent) {
    note.innerHTML += '<li>Error loading database.</li>';

  if (event.oldVersion < 1) {
    // Version 1 is the first version of the database.
    var store = db.createObjectStore("books", {keyPath: "isbn"});
    var titleIndex = store.createIndex("by_title", "title", {unique: true});
    var authorIndex = store.createIndex("by_author", "author");
  if (event.oldVersion < 2) {
    // Version 2 introduces a new index of books by year.
    var bookStore = request.transaction.objectStore("books");
    var yearIndex = bookStore.createIndex("by_year", "year");
  if (event.oldVersion < 3) {
    // Version 3 introduces a new object store for magazines with two indexes.
    var magazines = db.createObjectStore("magazines");
    var publisherIndex = magazines.createIndex("by_publisher", "publisher");
    var frequencyIndex = magazines.createIndex("by_frequency", "frequency");

request.onerror = function(event) {
  note.innerHTML += '<li>Error loading database.</li>';

request.onsuccess = function(event) {
  note.innerHTML += '<li>Database initialised.</li>';
  db = request.result;


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.

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support


23 — 57 webkit



10 — 16 moz

FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidOpera AndroidiOS SafariSamsung Internet
Basic support


23 — 57 webkit


25 — 57 webkit



Yes — 7.0 webkit

1. partial

See also

Document Tags and Contributors

Last updated by: fscholz,