Firefox container tabs let different tabs keep separate cookies, logins, and site data while staying in the same Firefox window. That means you can sign into two accounts on the same website at once, or keep work, personal, banking, and shopping sessions from mixing.
Does this affect you?
Use this for Firefox on Windows or Mac with Mozilla Firefox Multi-Account Containers. Containers are for organizing and isolating ongoing sessions. They are not the same as Private Browsing, which is meant to leave less local history behind.
Install Multi-Account Containers and open your first container tab
Mozilla provides the official extension for free.
- Open addons.mozilla.org in Firefox and search for Firefox Multi-Account Containers.
- Click Add to Firefox and approve the permission prompt.
- Click the new container icon in the toolbar.
- Choose one of the default containers, such as Personal, Work, Banking, or Shopping.
- A new tab opens with a colored container indicator.
- Sign into a website there, then open the same website in another container or regular tab with a different account.
Links opened from inside a container usually stay in that same container, so the whole browsing session remains isolated.
Create a custom container
Custom containers are helpful when the default names do not match your work.
- Click the container icon and choose Manage Containers, or open about:preferences#containers.
- Create a new container.
- Give it a name, such as Client A, School, or Side Project.
- Pick a color and icon so you can recognize it quickly.
- Save the container and open tabs from it like the built-in containers.
You can rename, recolor, or delete custom containers later from the same management screen.
More control
Always open a site in one container
When you are on a site, click the container icon and choose Always open in that container. From then on, Firefox routes that site into the assigned container even when you type the address or click a link.
Containers still save data
Container tabs keep cookies and logins between sessions, but separately per container. If you want a session that does not save normal history and cookies after closing, use a Private Browsing window instead.
Sync has limits
Firefox Sync can carry container names and colors to another computer, but open tabs and sign-in sessions remain device-specific. Logging in inside a container on one computer does not automatically log you in on another.
Sources
- Mozilla Support – Containers (2025)
- Mozilla Add-ons – Firefox Multi-Account Containers (2025)
- Mozilla Blog – Browse in a bubble with Firefox Containers (2024)