How to prevent Firefox from playing directly linked MP4 files in the browser

Firefox_25_Windows_8[1]
Oh hey classic MP4 functionality, nice seeing you again
Oh hey classic MP4 functionality, nice seeing you again

Every now and then a beloved piece of software acquires a new feature that sounds good on paper, but really breaks your workflow. This is the case with Firefox’s relatively new found ability to play directly linked MP4 files in the browser without a plugin. Nothing wrong with that, I just prefer to download such files – usually HD movie trailers – using DownThemAll and watch them later using VLC.

So here’s how you revert to the old handling of MP4 files:

  1. Enter about:config in the address bar
  2. Hit Enter
  3. Click I’ll be careful, promise!
  4. In the Search field, enter media.windows-media-foundation.enabled
  5. Double-click the True in the media.windows-media-foundation.enabled result to change it to False
  6. Close the browser tab

That should do it.

Author: jdrch

ISTJ, Rice Owl, UF Gator, mechanical engineer. STEM, sports, music, movies, humor. Account mine only & unaffiliated.

11 thoughts on “How to prevent Firefox from playing directly linked MP4 files in the browser”

  1. Thanks! It worked on the first computer (win7), the second computer (win7) needed the VLC-web plugin to also be disabled, computer 3 (vista) it worked (I installed VLC without the plugins) and on computer 4 (XP) it worked (no VLC)..

    Like

  2. This does not work. I’ve also seen posts stating that this will break HTML5 video playback.

    INSTEAD switching media.play-stand-alone to false worked for me.

    Like

Comment

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s