Microsoft explains how Edge's new feature "Sleeping Tabs" feature works

Microsoft is working on a new feature called “Sleeping Tabs” for its Edge browser. As you may have guessed it already, this new feature will put all your idle background tabs to sleep to save resources, thereby giving a boost to the performance of the browser.

Microsoft says Sleeping Tabs use 26% less memory and 29%  less CPU than a normal tab, which also translates into battery life savings.

The feature is currently available behind a flag called Enable Sleeping Tabs in Edge Canary 87.0.643.0. for Windows and Mac.

Today in a blog post Microsoft explained exactly how this feature works.

Sleeping tabs builds upon the core of Chromium’s “freezing” technology. Freezing pauses a tab’s script timers to minimize resource usage. A sleeping tab resumes automatically when clicked, which is different than discarded tabs, which require the page to fully be reloaded.

Sleeping tabs allows inactive background tabs to “go to sleep,” releasing system resources after a set amount of time. These resources include both memory and CPU and can be used for new or existing tabs or other applications running on your device.

By default, Microsoft has set tabs to go to sleep after two hours of inactivity. If two hours isn’t right for you, you can choose a different time interval in edge://settings/system. Tabs that are asleep will fade to let you know they’ve released resources.

To resume a sleeping tab, click on it like a normal tab. The tab will un-fade and your content will be there immediately. You can also add sites you never want to sleep to a block list in Settings.

With this technology, it is possible that some sites may not work as expected after they go to sleep. Microsoft says they have built heuristics to detect these scenarios and prevent those tabs from sleeping to keep you in your flow.

Sleeping tabs will be coming soon to Canary and Dev Channels [87.0.649.0]. Microsoft is asking for feedback on the feature, which can be delivered via Settings and more … > Help and feedback > Send feedback menu item.

Thanks, Leo Varela for the tip.