Windows – YouTube videos black, only audio in Firefox

firefoxhtml5videowindows 8.1youtube

When I play a YouTube video on my computer, it seems to play fine, but the whole video is black. This happens only when I play the video in Firefox.

I'm using Windows 8.1

What I did so far:

  • Restarting Firefox
  • Reloading the page with Ctrl+F5
  • Seeking back and forth in a video
  • Playing different videos, with and without playlist
  • Cleaning the cache, cookies, history and everything else…
  • Updating Firefox to the latest version
  • Disabling all extensions
  • Deactivating all plugins
  • Opening the video in a private window

Still the same…

I don't want to restart my PC or uninstall and reinstall Firefox, there must be a way around that.

And before I forget:

  • The video ads are black too.
  • HTML5 videos on other websites work fine.
  • I can see all the thumbnails of the video when moving the mouse over the seek bar.
  • The videos are not opening in Flash player through the browser – they are the HTML5 versions

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Best Answer

The Mozilla support forum has an entry for this problem and it relates to the browser using hardware acceleration causing the problem.


  1. Click the Firefox menu button
  2. Click Options
  3. Click Advanced
  4. Under General untick Use hardware acceleration when available

If you disable hardware acceleration it will fix the problem but it may cause problems elsewhere with, for example, WebGL and other browser graphics technologies.