Finally! This was a long awaited feature but this add-on is an elegant and powerful way to handle multi-accounts and profiles in Firefox. For those (as myself) who thought that profiles management was THE feature that lagged behind Chrome in Firefox, this now does more that catch up on it!

useful for keeping work and play separate!

One of the most useful add-ons I have ever tried. This really helps clean up account-hell if you want to keep your identities separated.

A useful extension.

It couldn't be easier to organize my sites into containers. Every feature I felt like I needed was already there to use and easy to find.

Very easy to use. The ability to keep categories of websites separate has greatly enhanced management of my privacy.

Just really useful! Hope it also had a "default site" for each container.

Funziona benissimo. In futuro aggiungerei anche la possibilità (opzionale) di tenere separata la cronologia tra i vari containers.

It will be great if the assigned sites and containers could be synced with the firefox account so users don't have to assign website on different devices separately.

Truly amazing extension.

Very buggy and misses important features.
Firstly: If you open a page in the incorrect container there is no way to easily reopen the page in a different container.
Always opening a page in a specific container is an option that is only presented when you have already opened the page in that specific container.
Even after asigning a page to a specific container, if for example you open such a page from a different container you will be presented with an interface to pick whether you want to open in default container or the current one. There is a "do not ask again" option but it doesn't function at all. You are always asked.
There is no administration page, no settings, no nothing. The only "option" is to remember the assigned container after you have already opened the page in the container, and, like I said, that feature DOESN't work well.
Containers also break some functionality. If you have facebook in container A and want to use facebook for login on a site on container B, this will not work.
This addon had the pottential to be a great feature but it's awfully implemented.

Très utile pour séparer différentes activités (notamment bancaires et commerciales) du reste de la navigation. D'autant plus que le paramétrage permet d'ouvrir systématiquement certains sites dans un container particulier

Best thing ever :)

Works as advertised, I can separate accounts with the containers with ease.

I hope this add-on can filter by wildcard, e.g. url like *.google.com.

This feature is sooo useful, especially with sites where you have multiple accounts. Or you don't want one site to leak to another! Or you visit, no soo safe for work sites!

This add-on is nearly essential. It safeguards my privacy, and it also keeps me organized. It's one of the first add-ons I download whenever I install firefox anywhere.

Handy for banking, keeping pesky trackers at bay, and using multiple twitter accounts.