As an intervention we want to limit the rate at which timers in out-of-view, cross-origin frames are able to fire. Until very recently it wasn't possible for script authors to easily determine whether their content was visible to the user or not. A common pattern therefore is to use a continuous setTimeout() loop for driving animations without considering visibility, which can be very costly for performance.
Status in Chromium
Browser Intervention (tracking bug) in:
- Chrome for desktop release 57
- Chrome for Android release 57
- Android WebView release 57
Consensus & Standardization
After a feature ships in Chrome, the values listed here are not guaranteed to be up to date.
- In development
- Positive
- Shipped/Shipping
- No signals
Owner
Last updated on 2021-01-02
Comments
A potential compatibility risk is that a site can observe timers firing out-of-order if the timers are scheduled from a mix of visible and hidden frames. To reduce this risk, we propose to only throttle timers in cross-origin frames.