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Firefox Beta

May 28, 2015

Version 39.0beta, first offered to Beta channel users on May 28, 2015



  • Improve performance of IPv6 fallback to IPv4

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

  • 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


  • Removed support for insecure SSLv3 for network communications

  • NPAPI Plug-in performance improved via asynchronous initialization

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

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


  • Drag and drop enabled for nodes in Inspector markup view

  • Web Console input history persists even after closing the toolbox

  • Cubic bezier tooltip now shows a gallery of timing-function presets for use with CSS animations

  • localhost is now available offline for WebSocket connections

Developer Information

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