This userscript blocks Page Visibility API and parts of Fullscreen API on Youtube and Vimeo, which are used to prevent background play even if your browser supports it.
- Install a script manager such as Violentmonkey.
- Click here to install the userscript.
NOTE: installing to your Chromium browser natively via the Extensions page might work but isn't supported. Chromium built in userscript support is very barebones, using a script manager is preferable.
Userscript code: MIT.
"Glasses" icon used in the logo by rahmatmasiv from the Noun Project under the CC BY 3.0 US.
The userscript injects a content script to replace the properties exposed, and stops events from propagating when applicable.
The userscript blocks visibilitychange event, and set document.hidden to be always false and document.visibilityState to be forever visible.
The userscript doesn't generally override the Fullscreen API because at the moment this is not required and the original implementation caused some broken UI after existing fullscreen.
As a site-specific workaround, we do however block fullscreenchange events on Vimeo to prevent playback from stopping when exiting fullscreen.
Some pages stop playback if they don't detect any user activity for a certain amount of time. To avoid this, the add-on ensures that the time of the last user activity is regularly updated.
As a demonstration, the content script currently injects itself to the following sites:
- youtube.com and youtube-nocookie.com
- vimeo.com