Firefox: Site Isolation coming in 2021

In order to make the browsing experience offered safer, Mozilla has now been working for over a year and a half with the goal of implementing a new feature called Site Isolation in Firefox. Already seen in action on Google's Chrome competitor (since release 67 in mid-2018), it manages each open page in a separate process so as to limit the action of malicious sites by preventing them from reaching out to the information conveyed through the other tabs.

Browser: Site Isolation on Firefox from next year

The project is known internally to the software house as Fission and whoever wishes can already put it to the test by downloading the Nightly version of the browser, typing " about: config ”(without quotes) in the address bar, then looking for the entries“ fission.autostart ”and“ gfx.webrender.all ”to give them the value“ true ”. After that, all you have to do is reboot.



Site Isolation development is taking a long time from Mozilla as it requires rewriting important portions of code. It has been the same for Google in recent years.

According to what has been announced, the functionality will reach the Stable channel (recently updated to version 82) by 2021. The software house emphasizes that its use makes the browser heavier in terms of resource use, especially as regards RAM, but at the same time it claims to be at work with the aim of introducing a series of optimizations in time so as to reduce its impact.

Source: ZDNet