Firefox 15 was released on August 28, 2012.[57]
This version includes a "Responsive Design View" developer tool,[96] adds support for the Opus audio format[97] and adds preliminary native PDF support (turned off by default).[98]
Silent updates automatically update Firefox to the latest version without notifying the user,[99] a feature that the web browsers Google Chrome and Internet Explorer 8 and above have already implemented,[100][101] although the user is able to disable that function.[102]
Mozilla improved regular startup time for Windows users.[103]