The count() method of the IDBObjectStore interface returns an IDBRequest object, and, in a separate thread, returns the total number of records that match the provided key or IDBKeyRange. If no arguments are provided, it returns the total number of records in the store.

Note: This feature is available in Web Workers.


var request = ObjectStore.count(optionalKeyRange);


A key or IDBKeyRange object that specifies a range of records you want to count.


An IDBRequest object on which subsequent events related to this operation are fired.


This method may raise a DOMException of one of the following types:

Exception Description
InvalidStateError This IDBObjectStore has been deleted.
TransactionInactiveError This IDBObjectStore's transaction is inactive.
DataError The specified key or key range is invalid.


In this simple fragment we create a transaction, retrieve an object store, then count the number of records in the store using count() — when the success handler fires, we log the count value (an integer) to the console.

var transaction = db.transaction(['fThings'], 'readonly');
var objectStore = transaction.objectStore('fThings');
var countRequest = objectStore.count();
countRequest.onsuccess = function() {


Specification Status Comment
Indexed Database API
The definition of 'count()' in that specification.
Editor's Draft  

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 count data Database IDBObjectStore IndexedDB Method Reference