How to Use Container Tabs in Firefox

Container tabs isolate cookies and site data into separate, named contexts, letting you stay simultaneously logged into multiple accounts on the same website — a work account and a personal account, for instance — in different tabs without either session interfering with the other. **Getting started**: container tabs require Firefox's Multi-Account Containers feature, either built into current desktop Firefox directly or added via Mozilla's own official extension in some versions, after which a colored container icon becomes accessible from the toolbar for opening new tabs scoped to a specific container. **No single default keyboard shortcut**: opening a new container tab isn't bound to a global keystroke by default — it's reached by clicking the Container icon in the toolbar and selecting which configured container the new tab should belong to, or by right-clicking a link and choosing "Open Link in Container" to open that specific link within a chosen container directly. **What genuinely gets isolated**: cookies, local storage, and site data are all kept separate per container, meaning a website sees each container as if it were a completely separate browser profile — logging into a site in a "Work" container and then opening the same site in a "Personal" container shows you as logged out (or logged in as a different account, if you've separately authenticated there) rather than sharing the same session across both. **How this differs from Private Browsing**: Private Browsing windows discard everything — history, cookies, form data — the instant they close, leaving no persistent session behind at all. Containers do the opposite: they maintain a genuinely persistent, separately logged-in session you can close and reopen later, picking up exactly where you left off within that specific container, which makes containers the better fit for regularly switching between multiple ongoing accounts, while Private Browsing suits a one-off session you deliberately don't want remembered at all. **Color-coding containers**: each container can be assigned its own color and icon during setup, which then shows as a colored line along the top edge of any tab belonging to that container — a quick visual reminder of which context you're currently in, useful for avoiding the specific mistake of, say, accidentally posting something from a personal account tab when you meant to be in a work-container tab. **Assigning specific sites to always open in a container**: beyond manually choosing a container each time, Firefox's container settings support configuring specific sites to always open within a designated container automatically, which removes the need to remember to select the right container manually every single time you navigate to that particular site. **Related privacy features**: containers work alongside, not instead of, Firefox's Enhanced Tracking Protection (covered on the privacy-customization category page) — the two features solve different problems, with containers isolating your own logged-in sessions from each other and tracking protection blocking third-party trackers from following you across unrelated sites regardless of which container you're browsing in. **Mistake to avoid**: assuming containers alone provide the same anonymity as a VPN or Private Browsing is a genuine misunderstanding — containers isolate site data and cookies between contexts you've deliberately set up, but they don't hide your IP address or browsing activity from your network or from the sites themselves the way a VPN does, and they don't discard history the way Private Browsing does; containers and those other privacy tools solve different, complementary problems rather than one substituting fully for another.