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 laggy, slow to start

  • 1 tontu
  • 2 am na jafe-jafe bii
  • 23 views
  • i mujjee tontu mooy TyDraniu

more options

FireFox works well for everything I need except for youtube. There is usually a 5-10 second delay before a video starts playing. And once it is playing the video will often stutter (audio stays fine). Overall the site just runs really slow. I've tried using a private window and the problem is present there without any of my extensions active. Also I've tested on Chrome and youtube runs much smoother in that browser. Please help?

FireFox works well for everything I need except for youtube. There is usually a 5-10 second delay before a video starts playing. And once it is playing the video will often stutter (audio stays fine). Overall the site just runs really slow. I've tried using a private window and the problem is present there without any of my extensions active. Also I've tested on Chrome and youtube runs much smoother in that browser. Please help?

All Replies (1)

more options

Hi, I can only think of Windows Defender bug that affected Firefox's performance. We're seeing a ~75% CPU usage reduction on YouTube with patched Defender when running Firefox.

Try to run a definition update of the Windows Defender.