This site will have limited functionality while we undergo maintenance to improve your experience. If an article doesn't solve your issue and you want to ask a question, we have our support community waiting to help you at @FirefoxSupport on Twitter and/r/firefox on Reddit.

Search Support

Avoid support scams. We will never ask you to call or text a phone number or share personal information. Please report suspicious activity using the “Report Abuse” option.

Learn More

Videos / mp4s will not play in Firefox on Mac

  • 1 jibu
  • 2 wana tatizo hili
  • 18 views
  • Last reply by cor-el

more options

I have mp4 video content served up by CDN that will not stream in my Firefox browser (35.0.1) on Mac OSx (10.10.1). It downloads the file and opens the file in QuickTime (the same is true in Chrome). It will stream perfectly in Safari. In preferences, I see QuickTime Plug-in 7.7.3 associated with mp4 content, but my QuickTime Player is 10.4. If I change the default to my QuickTime Player it does not change the behavior.

I have mp4 video content served up by CDN that will not stream in my Firefox browser (35.0.1) on Mac OSx (10.10.1). It downloads the file and opens the file in QuickTime (the same is true in Chrome). It will stream perfectly in Safari. In preferences, I see QuickTime Plug-in 7.7.3 associated with mp4 content, but my QuickTime Player is 10.4. If I change the default to my QuickTime Player it does not change the behavior.

All Replies (1)

more options

With what content type does the server send the files?

See also your previous thread about issues regarding server configuration.

You can check content types supported by a plugin on the about:plugins page.

I don't know what the current state for mp4 support in Firefox is for playing with the HTML5 media player.

  • bug 1043696 - Enable Apple PlatformDecoderModule for HTML5 video playback (MP4 playback on OSX)

Please do not comment in bug reports
https://bugzilla.mozilla.org/page.cgi?id=etiquette.html