Sleeping tabs reduce the resources used by inactive browser tabs. You can choose a timer and keep selected sites active.
Set the inactivity timer
- In Edge, open Settings and more > Settings > System and performance.
- Select Performance.
- Turn on Automatically put tabs to sleep.
- Under Put inactive tabs to sleep after a set time, choose an interval that fits your work.
Keep an important site active
In the same Performance section, find Always keep these sites active. Select Add site, enter its full URL, and select Add. Use the three-dot menu beside an entry to edit or remove it.
Check the result
Leave an ordinary background tab inactive beyond your chosen interval. Sleeping tabs normally fade; click one to resume it. Tabs playing audio or capturing your screen may stay awake.
If the timer behaves differently
Energy saver can shorten the sleeping-tab interval. Organization policies can also manage these settings. If a setting is locked on a work device, contact IT.
To disable sleeping tabs, return to Performance and turn off Automatically put tabs to sleep.
Source
Microsoft Support: Learn about performance features in Microsoft Edge
