This presentation from Chrome developers shows technical details regarding what happens to a web page when it goes into background (the user switches to another tab)
Freezing:
Freezing:
- ~2013: timers are stopped on mobile after 5 minutes
- M67: loading tasks are stopped on mobile after 5 minutes
- M68 (experiment): page is frozen on desktop after 1 hour without network activity
- M69: page will be frozen or discarded based on the API it uses
- ~2020: page will be frozen after loading
Throttling:
- 2011: setTimeout/setInterval are fired once a second
- M56: timers are delayed to limit CPU usage to 1%
- M68: workers are throttled
- 2018: non-timer tasks are throttled
- ~2020: page will be throttled during loading depending on the foreground activity
