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Is Firefox compatible with Apple's new operating system, Lion?


I just upgraded my operating system to Lion on my Mac and while pages load fine in Safari, many do not load properly with my favorite Firefox, i.e. photos not loading, formatting off. Can you help? Thanks, Carolyn

Additional System Details

Sites Affected


Installed Plug-ins

  • iPhoto6
  • Displays Java applet content, or a placeholder if Java is not installed.
  • The QuickTime Plugin allows you to view a wide variety of multimedia content in web pages. For more information, visit the QuickTime Web site.
  • Shockwave Flash 10.3 r181


  • User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:5.0.1) Gecko/20100101 Firefox/5.0.1

More Information

  • Top 25 Contributor
  • Moderator
624 solutions 8068 answers

There certainly appear to be teething troubles, which may be rather unexpected as development versions of Lion have been available for a while. I have found many technical references to problems, and formal filed bug reports and a reference to a "Release Rapid Response Team - 10.7 Operating System " but I have not personally stumbled across much info from Firefox/Mozilla directed at end users of Firefox.

There are several other threads in this forum (there is also a contributors thread: /forums/contributors/707160 ) but that does not yet have any information likely to be immediately useful to you.

From what I did notice: it seems possible Lion could be associated with some Firefox crashes, and that some Lion features do not fully work with Firefox.

Question owner

Thank you for your response. I hope this glitch is resolved soon. The main websites I use and manage are affected by this.