Why are YouTube clips now stuttering in my browser when they worked fine a couple of days ago?
All of a sudden Youtube clips are stuttering and twitching when played through Firefox, while a couple of days ago everything was smooth and fine.
All Replies (3)
Are you playing YouTube videos with Flash or HTML5? You can check by visit youtube.com/html5
It appears to be HTML5 (when possible), according to that link. Except for "MSE & WebM VP9 ", whatever that is.
Hello,
Try Firefox Safe Mode to see if the problem goes away. Firefox Safe Mode is a troubleshooting mode that temporarily turns off hardware acceleration, resets some settings, and disables add-ons (extensions and themes).
If Firefox is open, you can restart in Firefox Safe Mode from the Help menu:
- Click the menu button
, click Help 
and select Restart with Add-ons Disabled.
If Firefox is not running, you can start Firefox in Safe Mode as follows:
- On Windows: Hold the Shift key when you open the Firefox desktop or Start menu shortcut.
- On Mac: Hold the option key while starting Firefox.
- On Linux: Quit Firefox, go to your Terminal and run firefox -safe-mode
(you may need to specify the Firefox installation path e.g. /usr/lib/firefox)
When the Firefox Safe Mode window appears, select "Start in Safe Mode".
If the issue is not present in Firefox Safe Mode, your problem is probably caused by an extension, theme, or hardware acceleration. Please follow the steps in the Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems article to find the cause.
To exit Firefox Safe Mode, just close Firefox and wait a few seconds before opening Firefox for normal use again.
When you figure out what's causing your issues, please let us know. It might help others with the same problem.