Firefox Release

July 2, 2015

Version 39.0, first offered to Release channel users on July 2, 2015

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



  • Improve performance of IPv6 fallback to IPv4

  • Fix incomplete downloads being marked as complete by detecting broken HTTP1.1 transfers

  • A regression that could lead to Flash not displaying has been fixed

  • Security state indicator on a page now correctly ignores loads caused by previous pages

  • Fixed an issue where a Hello conversation window would sometimes fail to

  • Various security fixes


  • Removed support for insecure SSLv3 for network communications

  • Performance of displaying dashed lines is improved (Mac OS X)

  • Malware detection service for downloads now covers common Mac file types


Web Platform

All Firefox downloads