Firefox 42 and previous versions offer a preference in about:config called full-screen-api.approval-required, by toggling its value to false we can able to disable YouTube.com is now fullscreen message. Some developments have happened in version 43: Mozilla has improved full screen notifications experience in Firefox 43.
The dialog appears for a few seconds (unlike to earlier versions, doesn’t ask for permissions) and goes away automatically after that without needing any interaction from the user. But when the user moves the mouse or presses any key on the keyboard, full screen dialog appears again.
Mozilla removes the Old Search UI from Firefox
Firefox 43+: Remove ‘youtube.com is now full screen’ notification
Firefox 43+ doesn’t offer ‘full screen api approval required’ hidden preference, it has been removed. But you can still disable the message in version 43, here is how.
- Visit about:config
- Find the preference full-screen-api.warning.timeout and change its value to 0 from the default 3000.
- Done.
How to Restore Firefox’s Old Search UI and Preferences Window
Note: Remember this feature was designed in browsers to avoid phishing attacks, that’s a security measure, if it’s not bothering you, leave it.
Thanks again. After the fix for v42 (Mac), I thought it was over. Then an update and the same old problem came back. Why must developers constantly make things purposely inconvenient and overly complicated? Do they even use the products they design?
I got here because they first removed “full-screen-api.approval-required”. Now that I learned from the article, that I have to set “full-screen-api.warning.timeout” instead, I am surprised they removed that option again. How to stop users from updating? Firefox can tell.
Excellent, it worked! I’m not sure why we needed that “warning” in the first place.
That’s there to avoid phishing attacks, its a security measure, read this http://feross.org/html5-fullscreen-api-attack/
This worked, but later my youtube window went full screen and I can’t remember which key to bring it back. I’m lost. Help! jk! :)
Talking about full screen or full screen notification? F11 activates the full screen.
Thankyou Thankyou Thankyou Thankyou Thankyou Thankyou !
Is there anyone in the world who used a PC in the last 5 yrs who doesn’t know that you “press to exit full-screen”? I tried to call YouTube to let them know… What a cluster!
BTW… Turn PC “ON” before trying to browse…. :-) O_0