it Containers were already a "killer feature" of Firefox, this is like a weapon of mass destruction feature.

This extension means you can save a bookmark which opens gmail (or drive or calendar) in different containers for different accounts. Because the URL is the same for different gmail accounts, the standard feature of associating a URL with a dedicated container doesn't work: it's the same url for each gmail account, so they always open in the same container. This add-on solves the problem.

This is very convenient.

The notes are not very clear on how to do this.
Do it like so, taking gmail as the example.

Let's say you already have a Work and a Personal container.

First, use the Firefox container tool to remove any rules you have added which force gmail to open in a particular container. Such sites appear in a menu linked to the container name.


Add two bookmarks. You could go to gmail, and bookmark it, if you don't already have gmail bookmark

The normal URL is
https://mail.google.com/mail/u/0/#inbox

edit the bookmark to be

ext+container:name=Work&url=https://mail.google.com/mail/u/0/#inbox

then copy this bookmark to make a second one, and edit the bookmark to be
ext+container:name=Personal&url=https://mail.google.com/mail/u/0/#inbox

I've never posted a review before for a Firefox add-on, but this one is so elegantly implemented (and so sorely needed) that I felt compelled to do so.

This add-on is a simple solution to a vexing problem of how to force a bookmark to open in a specified container every time. Kudos to the developer!

If it's not entirely clear from the add-on description, once you've installed this add-on, you can replace any Firefox bookmark with the ext+container command syntax and that bookmark will always open in the specified container automatically. For example, if you have a bookmark to www.google.com that you want always to open in your Google container, first make sure you've created a container named Google, then right-click on your bookmark, select Properties, and change the location from https://www.google.com/ to ext+container:name=Google&url=https://www.google.com/

One note to other users: If your container's name has any spaces or other special characters in it, you have to urlencode the special character in the command (like replacing spaces with %20). For example, if you want your bookmark for www.bigbank.com to open in your My Banks container, the bookmark would be ext+container:name=My%20Banks&url=https://www.bigbank.com/

I would rate it 10 over 5. The add-on says what it does and does what it says. It may seem obvious but I'd like to suggest the developer to highlight that if a bookmark adheres to the "ext+container:name=MyContainer&url=" syntax it will open in "MyContainer" directly. That's a very good thing to have

Does what it says and does it right.
I love this.

Works well with bookmarks! Thanks!

I have been waiting for something like this for a long time. I can finally set up my password manager to open different accounts on the same site in different containers.

Edit 09 May 2020
Here is an example you can share. I use KeePass 2 password manager, which allows an override URL for specific entries. I have two Amazon accounts, which I open in different containers. In the Override URL field of both, I put
cmd://{FIREFOX} ext+container:name={GROUP}&url="{URL}"

The entry I put in KeePass' Work folder automatically expands to
"C:\Program Files\Mozilla Firefox\firefox.exe" ext+container:name=Work&url=https://smile.amazon.com/

The entry I put in KeePass' Personal folder expands to
"C:\Program Files\Mozilla Firefox\firefox.exe" ext+container:name=Personal&url=https://smile.amazon.com/

Exceptionally useful.