[0x49d1]

But why is this REALLY "more powerful than first party isolation"? I don't need this feature every day, in case I do - just create separate profile and it's easy to run it right from toolbar. The only usecase I can remember: specific domains can be automatically opened in container - and that's a good feature to have, but not really a dealbreaker. Another difference: organization as a tab in the same window - not that really needed, just a different UI for not commonly used feature.

[thrwawy74]

I use this with the Temporary Containers extension, so every tab is a new container, and a new session to the website I'm visiting. When I close the tab/container, all information about that site is lost. My browsing behavior - by default - is cookies live for as long as the container lives (and other cached elements). It makes me feel safer, browsing online, that I have to opt-in to remembering cookies and having them persist longer than the container. I can assign things over to the static containers like work-play-etc. For development I can have several tabs open with several independent sessions/logins going to the same website. When I tried to do this with Chrome it was 'clunky' to run separate Chrome profiles, which seem to be separate instances. I do remember an extension to do multiple in-the-same-browser sessions, but it was using a 3rd party service. I can have multiple sessions going in the same window in Firefox. As I understand, FPI prevents caching being used as a means to spy where you've been. My naive understanding is that containers encompass more than the cached elements FPI segregates, including things like fonts or localstorage. (I'm probably wrong) The only blindspot I see in Firefox is I wish preferences for extensions were per-container as well. I still use uMatrix, so if I've unblocked JS for a domain in 1 container, I don't want it unblocked for the same domain in an entirely separate container.

Also, for some sites where I do "Sign in with Google", I like being able to 'stitch together' those session cookies by opening sites in the "Google" container so i can just waltz right into the "other site". On my other containers, they don't have the session cookie for Google in the background so I'm good. I use this for work-related things with SSO. Instead of naming the "static containers" "Work, Play, etc", I just call them the SSO-provider, and I know if I move an existing container into that or open a new tab using that container it will have the login I need.

My default settings are pretty locked down. Umatrix blocks a lot in my new temporary containers, and then I gradually unblock things.

[ajolly]

Wait, Firefox handles extension preferences globally? This is exactly what I've been wishing Chrome would do. I've spent a ton of time writing weird scripts and hacking Chrome to copy and sync various extension preferences from one profile to another.

Of course ideally I could specify specific extensions to work globally vs per profile.

(I'm perfectly fine having different profiles use different windows)

[superdeeda]

When I worked for an agency, I used this feature ALL the time. It had to be easy for me to switch between, for example, Trello boards of different clients or different Datadog accounts.

Even now, working at a single company, I use multi-account containers to keep tabs open for our different AWS and Datadog accounts.