The open() method of the IDBFactory interface requests opening a connection to a database.

The method returns an IDBOpenDBRequest object immediately, and performs the open operation asynchronously. If the operation is successful, a success event is fired on the request object that is returned from this method, with its result attribute set to the new IDBDatabase object for the connection.

If an error occurs while the database connection is being opened, then an error event is fired on the request object returned from this method.

May trigger upgradeneeded, blocked or versionchange events.

Note: This feature is available in Web Workers.


For the current standard:

request =[, version])

For the experimental version with options (see below):

request =[, options])


The name of the database.
Optional. The version to open the database with. If the version is not provided and the database exists, then a connection to the database will be opened without changing its version. If the version is not provided and the database does not exist, then it will be created with version 1.
options (version and storage)
Optional. In Gecko, since version 26, you can include a non-standard options object as a parameter of that contains the version number of the database, plus a storage value that specifies whether you want to use persistent or temporary storage.

Note: You can find out more information on the different available storage types, and how Firefox handles client-side data storage, at Browser storage limits and eviction criteria.


A IDBOpenDBRequest object on which subsequent events related to this request are fired.


This method may raise a DOMException of the following types:

Exception Description
TypeError The value of version is zero or a negative number or not a number.


Example of calling open with the current specification's version parameter:

var request ="toDoList", 4);

Example of calling open with the options parameter:

var request ="toDoList", {version: 4, storage: "temporary"});

In the following code snippet, we make a request to open a database, and include handlers for the success and error cases. For a full working example, see our To-do Notifications app (view example live.)

var note = document.querySelector("ul");

// In the following line, you should include the prefixes of implementations you want to test.
window.indexedDB = window.indexedDB || window.mozIndexedDB || window.webkitIndexedDB || window.msIndexedDB;
// DON'T use "var indexedDB = ..." if you're not in a function.
// Moreover, you may need references to some window.IDB* objects:
window.IDBTransaction = window.IDBTransaction || window.webkitIDBTransaction || window.msIDBTransaction;
window.IDBKeyRange = window.IDBKeyRange || window.webkitIDBKeyRange || window.msIDBKeyRange;
// (Mozilla has never prefixed these objects, so we don't need window.mozIDB*)

// Let us open version 4 of 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 later on, for opening transactions and suchlike.
  db = DBOpenRequest.result;


Specification Status Comment
Indexed Database API
The definition of 'open()' in that specification.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 23webkit
10 moz
16.0 (16.0)
10, partial 15 7.1
Available in workers (Yes) 37.0 (37.0) ? (Yes) ?
Feature Android Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile
Basic support 4.4 22.0 (22.0) 1.0.1 10 22 8
Available in workers (Yes) 37.0 (37.0) (Yes) ? (Yes) ?

See also


© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.

API Database IDBFactory IndexedDB Method open Reference storage Storage