Multi-Account Containers is a Firefox add-on that lets you separate your work, shopping or personal browsing without having to clear your history, log in and out, or use multiple browsers. It's an improved version of the Containers feature built into Firefox Nightly and the now completed Firefox Containers Test Pilot experiment.

What are Containers?

Container tabs are like normal tabs except that the sites you visit will have access to a separate slice of the browser's storage. This means your site preferences, logged in sessions, and advertising tracking data won't carry over to the new container. Likewise, any browsing you do within the new container will not affect your logged in sessions, or tracking data of your other containers.

How to use Multi-Account Containers

Install the Firefox Multi-Account Containers extension from the Mozilla Add-ons website. To open Containers, look for the Containers icon in the Firefox toolbar:

Click on it and select the container you want to open.

Note that Containers is disabled in Private Browsing and when Never Remember History is selected in your privacy preferences.

You can open new Container tabs and each one will keep separate browser storage (such as cookies or localStorage) from other Containers. Your normal tabs are the default container and will still look and act as you'd expect them to before enabling containers.

Open links in new tabs and containers

You can open links in a new and/or different container. Right-click on any link, select Open link in New Container Tab, and then select the desired container tab.Hold the control keyCommand key while clicking a link to open it in a new tab. The new tab will open within the same container as the previous tab. This includes both the default container and in any of the predefined containers.

What you can do with Multi-Account Containers

1. Log in to multiple accounts on a single website at the same time. For example, if you have a personal Gmail account and a work Gmail account, you can log in to both accounts in separate containers.
2. Protect yourself against tracking without having to log out of websites while you browse. Websites in one container can't track your activity in other containers.
3. Protect yourself against Web security attacks. Any harmful clicks will be kept within that website's container, so attackers won't be able to hijack your information in other containers.
4. Assign a website to a container, so that a specific website will always open in a specific container. This helps protect from accidents, stopping you from accidentally visiting a shopping site in your banking container, for example.
5. Hide and Show: Assume you use your browser for both Work and Personal tasks. When you come home at the end of the day, you don’t want to be thinking about “Work” anymore, but your browser is full of Work tabs. You can “Hide” your Work tabs and proceed with your Personal tasks. Then the next day, when you are back at work, you can “Hide” your Personal tabs and “Show” your Work tabs.
6. Sort: The Container Menu has a “Sort Tabs” option and a “Move tabs to a new window” option. Sort Tabs will put all your tabs of the same container type next to each other in a given browser window. So if you have “Work” and “Personal” tabs interleaved within each other, you can easily sort them to help organize your tasks (as seen below). “Move tabs to a new window” will take all the container tabs in your current window and move them to a fresh window.