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.

53.0

Firefox Release

April 19, 2017

Version 53.0, first offered to Release channel users on April 19, 2017

Today's Firefox release makes Firefox faster and more stable with a separate process for graphics compositing (the Quantum Compositor). Compact themes and tabs save screen real estate, and the redesigned permissions notification improves usability. Learn more on the Mozilla Blog.

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

New

  • Improved graphics stability for Windows users with the addition of compositor process separation (Quantum Compositor)

  • Two new 'compact' themes available in Firefox, dark and light, based on the Firefox Developer Edition theme

  • Lightweight themes are now applied in private browsing windows

  • Reader Mode now displays estimated reading time for the page

  • Windows 7+ users on 64-bit OS can select 32-bit or 64-bit versions in the stub installer

Fixed

Changed

  • Updated the design of site permission requests to make them harder to miss and easier to understand

  • Windows XP and Vista are no longer supported. XP and Vista users running Firefox 52 will continue to receive security updates on Firefox ESR 52.

  • 32-bit Mac OS X is no longer supported. 32-bit Mac OS X users can switch to Firefox ESR 52 to continue receiving security updates.

  • Updates for Mac OS X are smaller in size compared to updates for Firefox 52

  • The last few characters of shortened tab titles fade out instead of being replaced by ellipses to keep more of the title visible

  • Ended Firefox Linux support for processors older than Pentium 4 and AMD Opteron

  • New visual design for audio and video controls

Developer

  • Support for WebM video with alpha, which allows playing videos with transparent backgrounds

  • Changes for web developers

Developer Information