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

YouTube won't stay fullscreen with music muted

more options

Whenever I play videos on YouTube, they won't stay fullscreen unless the volume is on. Muted or turned right down and they won't stay in fullscreen. It's really annoying because I would like to view videos and not have to listen to annoying background music that some video makers feels is imperative to the video.

Not sure anyone has come across this before

Whenever I play videos on YouTube, they won't stay fullscreen unless the volume is on. Muted or turned right down and they won't stay in fullscreen. It's really annoying because I would like to view videos and not have to listen to annoying background music that some video makers feels is imperative to the video. Not sure anyone has come across this before

All Replies (1)

more options

Are you using keyboard key to mute?

Start Firefox in Safe Mode to check if one of the extensions (Firefox/Tools > Add-ons > Extensions) or if hardware acceleration is causing the problem (switch to the DEFAULT theme: Firefox/Tools > Add-ons > Appearance).

To Enable SafeMode

  • You can open Firefox 4.0+ in Safe Mode by holding the Shift key when you open the Firefox desktop or Start menu shortcut.
  • Or open the Help menu and click on the Restart with Add-ons Disabled... menu item while Firefox is running.
  • Once you get the pop-up, just select "'Start in Safe Mode"

If it works in Safe Mode and in normal mode with all extensions (Tools > Add-ons > Extensions) disabled then try to find which extension is causing it by enabling one extension at a time until the problem reappears.

Close and restart Firefox after each change via "Firefox > Exit" (Windows: Firefox/File > Exit; Mac: "Firefox > Quit Firefox"; Linux: "Firefox/File > Quit")