See what’s new in Firefox!

Release Notes tell you what’s new in Firefox. As always, we welcome your feedback. You can also file a bug in Bugzilla or see the system requirements of this release.


Firefox Release

August 6, 2013

Version 23.0, first offered to Release channel users on August 6, 2013

We'd also like to extend a special thank you to all of the new Mozillians who contributed to Firefox 23!


  • Mixed content blocking enabled to protects users from man-in-the-middle attacks and eavesdroppers on HTTPS pages (learn more)

  • Options panel created for Web Developer Toolbox



  • "Enable JavaScript" preference checkbox has been removed and user-set values will be reset to the default

  • Updated Firefox Logo

  • Improved about:memory's functional UI

  • Simplified interface for notifications of plugin installation

  • Enabled DXVA2 on Windows Vista+ to accelerate H.264 video decoding

  • Users can now switch to a new search provider across the entire browser

  • CSP policies using the standard syntax and semantics will now be enforced

  • Replace fixed-ratio audio resampler in capture code with Speex resampler and eliminate pseudo-44000Hz rate

  • <input type='file'> rendering improvements (see bug 838675)

  • "Load images automatically" and Always show the tab bar" checkboxes removed from preferences and reset to defaults. Want to hide one tab? Try this add-on.


  • Dropped blink effect from text-decoration: blink; and completely removed <blink> element

  • New feature in toolbox: Network Monitor

  • Social share functionality

  • HTML5 <input type="range"> form control implemented

  • Write more accessible pages on touch interfaces with new ARIA role for key buttons

  • Implemented a global browser console

  • Added unprefixed requestAnimationFrame

Developer Information


  • If you try to start Firefox using a locked profile, it will crash (see 573369)