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:

var IDBOpenDBRequest =;
var IDBOpenDBRequest =, version);


The name of the database.
version Optional
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.

Experimental Gecko options object

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.
Warning: The storage attribute is deprecated and will soon be removed from Gecko. You should use StorageManager.persist() to get persistent storage instead.

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.

Return value

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);

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 2.0
The definition of 'open()' in that specification.
Indexed Database API Draft
The definition of 'open()' in that specification.

Browser compatibility

ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
openChrome Full support 24
Full support 24
No support 23 — 24
Prefixed Implemented with the vendor prefix: webkit
Edge Full support 12Firefox Full support 16
Full support 16
No support 10 — 16
Prefixed Implemented with the vendor prefix: moz
IE Partial support 10Opera Full support 15Safari Full support 7WebView Android Full support Yes
Full support Yes
No support ? — ?
Prefixed Implemented with the vendor prefix: webkit
Chrome Android Full support 25Firefox Android Full support 22Opera Android Full support 14Safari iOS Full support 8Samsung Internet Android Full support 1.5


Full support
Full support
Partial support
Partial support
Requires a vendor prefix or different name for use.
Requires a vendor prefix or different name for use.

See also