A good add-on for keeping some activities separate from each other. The only bad thing that I can say about it is that the icon looks great in default and light mode, but when I switch to dark mode, I can barely see the icon. Still a good add-on, does what it says on the tin.

This functionality is welcome. What was previously managed with multiple browser accounts can now be managed with only one (provided I use the same add-ons).
A few things that would make its initial and possibly regular use more convenient in my case, mainly different ways to sort websites into a container and make it defualt.
--ability to import bookmarks and bookmark folders so that they defualt to a specific container.
--ablity to sort "current tab" and "all open tabs" into a specific container when clicking on the add-on icon
--had minor issues with [are you sure you want to open this site in this container by defualt] message where it was sometimes unresponsive (I added an entire bookmark folder to a container and opened all at once) I mostly had to wait and reload before confirming.
--The ability to generally avoid/disable the [do you want this to defualt to this container] without individually using the [rmember for this site] setting might be welcome.
Consideration: if I'm already in a particular container and link to a site that would normally use a different container I would most likely not want it to instead remain in the current container or have me decide, unless in the defualt container. If the [remember for this site] option is not selected the message does serve that purpose but it's not useful when opening bookmarks. So implementation may have to be complicated or have to allow for various rules that are dependent on the current container.

This is an awesome add-on for Firefox. It's like having 2+ browsers within a single window. You can log into two different email accounts within the same window! You can open up two Amazon.com accounts via two different colored Containers! It's so awesome! User Interface Power to the MAX!

Personal Example: I have like 8 gmail accounts and it's a hassle to log into each account and check them via PC browsers (Thank goodness for the mobile gmail app, but sometimes you just gotta view an email from a PC). But with Firefox containers, I can easily open all 8 gmail accounts, each within it's own container. For example: my first, main gmail opens in a blue container. My second, secondary gmail opens in a red container. My third, junk email opens in a yellow container. I literally press the containers button, pick a color, open a new tap in said color, type in gmail.com or press the home button, and (since I have Firefox remember my passwords to my gmail accounts) it automatically loads just that email (for that color). In essence, I can check all 3 emails within a single browser window. Containers is convenient!

Technical Note: I've streamlined getting to my emails faster. I use another Firefox Quantum add-on, "New Tab Override" by Soren Hentzschel to actually get Firefox Quantum to automatically open a new tab specifically assigned to https://mail.google.com/. Now I can just: pick a container color (blue, red, yellow) and open a "new tab" in said color, and with "New Tab Override," I'm automatically redirected to https://mail.google.com/ . Yes, every time I open a new tab I'm redirected to https://mail.google.com/ but now I no longer have to type "gmail.com" into the url bar nor press the home button to load gmail for each of my container colors. That's 8 less clicks for me and I get to have Facebook be my homepage again!

Edit: Be careful when first opening up Firefox Quantum. You won't be in any Container. Instead you will be in a colorless container a.k.a. normal Firefox browser/window/tabs (vanilla Firefox). If anything, I ask that the developers make it so I can start Firefox in a specific colored Container. Also be careful when opening up a new tab in Firefox Quantum, the default new tab is a vanilla tab so you must hold the + symbol to open a specifically colored new tab.

Muito útil este add-on...

Seria perfeito se pudesse ser utilizado algumas ideias do add-on chamado "Temporary Containers", pois ele e meio difícil de entender .

Obrigado Moz & Dev's !!!

Unfortunately broken right now. It's a very good extension when it is working properly. For now though, the automatic 'open in the right container; always' option is not working properly. (Maybe for certain sites (some of the ones I use))

Love it, only wish there was a keyboard shortcut for opening up tab in a specific workspace without having to tab. Would be nice if I could at least assign some.

Finally I can easily maintain different AWS sessions in a single browser. Thanks!

Not really useful without the ability to sync and to move or copy cookies and site data when reassigning a site to another container