This API is available on Firefox OS for internal applications only.

The clear() method of the DataStore interface deletes all records from the data store, leaving it empty.

Note: The Data Store API is available in Web Workers, from Firefox 32 onwards (Firefox OS 2.0; see bug 949325.)


store.clear().then(function(success) {
  // Do something with success, which is a boolean 
  // reporting whether the deletion was successful or not


A Promise object of type void that resolves with boolean reporting whether the deletion was successful or not.


You can specify an optional parameter that will be a revisionId (a DOMString). This can be used to prevent conflicts. If the revisionId is not the current revisionId for the current Data Store, the operation is aborted. This means that the developer has a 'old' revisionId and will have to manage the conflict somehow.


The following example gets all the data stores on the device called "contacts", then deletes all the content in the first "contacts" data store:

navigator.getDataStores('contacts').then(function(stores) {
  stores[0].clear.then(function(success) {
    if(success) {
      console.log('Contacts successfully cleared.');


Specification Status Comment
Data Store API
The definition of 'clear()' in that specification.

The discussion concerning this API's creation happened in various Mozilla mailing lists and other places. A summary of the discussion and further pointers can be found on the Mozilla Wiki. For further feedback and questions, send mail to the dev-webapi mailing list.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support No support No support No support No support No support
Feature Android Chrome Firefox Mobile (Gecko) Firefox OS IE Phone Opera Mobile Safari Mobile
Basic support No support No support No support 1.0.1 No support No support No support
Available in web workers No support No support No support 2.0 No support No support No support

See also

Document Tags and Contributors

 Contributors to this page: chrisdavidmills, fscholz
 Last updated by: chrisdavidmills,