The latest Chrome update comes with something a lot of people will be rejoicing for – minimising power usage.

According to the blog, starting from Chrome version 57, they will be minimising power impact from things users can’t see. “This includes background tabs, which consume a third of Chrome’s power usage on desktop. Starting in version 57, Chrome will throttle individual background tabs by limiting the timer fire rate for background tabs using excessive power.”

Basically, the way it works is, each tab will be given a timer and after 10 seconds of it being not in focus, the browser will delay the timers, limiting the average CPU load to 1% of the core if it runs over their budget. However, tabs playing audio or maintaining real time connections – like WebSockets or WebRTC – will still run and is considered foreground.

According to the post, “We’ve found that this throttling mechanism leads to 25% fewer busy background tabs.” In the long term however, Google has bigger plans. Ideally they are planning for background tabs to be fully suspended, relying instead on new APIs for service workers to do work in the background. 

If you really want to know the nitty gritty of how it works, Google’s developer pages explains it. And for their long term plan, look here.