This is not new, and it's weird that this blog post doesn't acknowledge that.

A a snapshot from 2017 [0] of their docs show the UI for this very feature. A snapshot from 2023 of their knowledge base [1] says that "Firefox Containers is a basic built-in feature".

I just created a new profile in Firefox 140 ESR, started it in safe mode (which disables extensions), enabled "privacy.userContext.enabled" in about:config - and there you go, native containers accessible from File -> New Container Tab.

I'm not talking about the Multi-Account Containers extension. There are no extensions installed or enabled. It comes with Firefox 140 ESR, without extensions.

The Containers feature is already a "native, first-party feature" in older versions of Firefox. Firefox already has a "first-party version of containers". They have already brought it "directly into the heart of Firefox for all to benefit".

So what are they talking about in this blog post? Are they simply flipping the config setting to true by default? Are they replacing the existing "Containers" feature with a new feature which is also called "Containers"? Are they rebranding the Multi-Account Containers extension as "Containers" and making it built-in (seemingly not, since apparently "Not all of the features of the add-on are available in the first-party version of containers").

[0] https://web.archive.org/web/20170821073747/https://developer...

[1] https://web.archive.org/web/20230307151023/https://support.m...