How to use containers in Firefox easily and advancedly

If you use Firefox daily and manage multiple email accounts, social media profiles, or work tools, Firefox Containers can change the way you browse . This feature lets you separate your different "online lives" into individual tabs within the same browser, without getting overwhelmed with windows, private sessions, or multiple browsers.

The most striking thing is that, with the Firefox Multi-Account Containers extension, you can log in to multiple accounts of the same service simultaneously from a single Firefox profile: two Gmail accounts, two Outlook accounts, several Teams accounts, different social media accounts... all together, organized, and without mixing cookies or data.

What are Firefox containers and what are they used for?

Essentially, containers are a way for Firefox to separate storage for each website tab . Each container tab functions like a small "subbrowser" within Firefox: cookies, login information, and other data are stored independently and are not shared with other containers.

This allows you to have, for example, one tab with your work email and another with your personal email , both open at the same time, without one closing the session of the other. You don't need to switch profiles, open private browsing, or use multiple browsers to achieve this.

Firefox presents this feature, through its official extension, as a way to create a container for each facet of your digital life : one for "Personal", one for "Work", one for "Banking", one for "Shopping"... And you can add as many as you want, with their own color and icon to distinguish them effortlessly.

An important detail is that, although the idea might remind you of having different user profiles in the browser, it's not the same as profiles in Firefox or other browsers . Containers reside within a single profile and focus on isolating sessions and cookies for each service, not on separating bookmarks, history, or extensions.

Thanks to this, Firefox becomes more than just a simple browser : it can replace applications such as specialized webmail clients, multi-tab tools like Rambox, or panels to manage different accounts in the style of a TweetDeck, all within the browser itself and expandable with other extensions.

Firefox Multi-Account Containers Extension: The Gateway

Although containers are built into Firefox, the easiest way to use them is through the official Firefox Multi-Account Containers extension , developed by the Mozilla Foundation. There's no need to get bogged down in advanced settings: the extension activates the feature and adds a button to the toolbar to manage everything with just a couple of clicks.

In fact, this extension could almost be considered more of a "switch" and a visual interface than an external add-on, because containers are a native feature of the browser . They were initially introduced as an experimental option and later encapsulated in an official plugin for ease of use.

The interesting thing is that once you start using it, even if you disable or uninstall the extension, the container settings remain . You'll still have access to them from your browser preferences and the context menu of the new tab button, and you can even sync them across devices with your Firefox account.

Mozilla also offers, in some cases, a standalone extension called Firefox Containers, configured by URL, which pre-configures containers for specific services and may come pre-installed. But the core component remains Multi-Account Containers, which is what truly gives you complete control.

Furthermore, the integration of containers with Mozilla VPN allows each container to independently protect its traffic and location . This means you could, for example, connect to a server in your country to access online banking, while in another container tab you shop at a foreign store using a different server.

Key advantages of using containers in Firefox

One of the biggest practical advantages is being able to log into multiple accounts for the same service simultaneously . You can have two Gmail accounts, several Outlook accounts, different Microsoft Teams accounts , or various client dashboards open without constantly logging out and back in or using a different browser.

This capability allows Firefox to compete even with dedicated multi-account management applications, since everything is managed by tabs within the same window . Having ten different browser windows open is not the same as having ten color-coded and categorized tabs within a single Firefox window.

Another major advantage is privacy: by separating sites and activities into containers, cookies and trackers are confined to their own sphere . Cookies downloaded to one container cannot be used in others, making it difficult for tracking companies to build a single, comprehensive profile of you.

If you typically browse without containers, all your activity is associated with a single set of cookies; with containers, your activity is fragmented into several independent profiles . If you organize your digital life into ten different containers, trackers will, in practice, see ten distinct profiles that they cannot reliably link to one another.

It also greatly helps with daily organization: you can use containers to clearly separate your personal, work, financial, and leisure browsing . For example, one for your bank account, another for online shopping, another for social media, another for professional projects, and so on.

From a productivity standpoint, this makes Firefox especially attractive for those managing accounts for multiple clients : marketing agencies, consultants, freelancers, technical support, etc. You can have a container for each client, with their email accounts, cloud tools, and social media, all isolated from the rest.

Practical use cases: work, clients, and personal life

In everyday use, one of the most common applications of Multi-Account Containers is as a manager of multiple accounts at work . If you work with several clients, you can dedicate a container to each one: “Client 1”, “Client 2”, “Project X”, “Project Y”, and so on.

In each container, you can open Microsoft Teams, Outlook, Gmail, or other client-specific accounts without them interfering with your personal accounts or those of other projects. When you're working for a client, you simply go to their container and have their entire environment ready.

Another very real example: if you use Gmail for both your personal and professional email, containers allow each account to live permanently in its own tab . In one container you'll have your personal Gmail, in another your blog's Gmail, and in another your work Gmail—all active without interfering with each other.

The same applies to social media or advertising platforms: you can separate personal accounts from accounts used to manage pages, ads, or projects . This prevents silly mistakes like posting something to the wrong account simply because you were logged into the wrong one.

Even if you just want a convenient way to keep your shopping, online banking, and social media separate , containers let you create dedicated tabs for each type of use. For example, a "Shopping" container for online stores and a "Banking" container for your bank account, keeping each area isolated.

How to install Firefox Multi-Account Containers step by step

Installing the extension is extremely simple, because Mozilla distributes it from its own official catalog. To begin, simply access the extension's page at addons.mozilla.org , at the following URL:

https://addons.mozilla.org/es/firefox/addon/account-containers/

Once on the page, you'll see a prominent button labeled "Add to Firefox" . Clicking it will open a pop-up window in your browser asking you to confirm the extension installation and detailing the permissions it needs to function.

In that window, simply click "Add" to complete the installation . Firefox will download the extension, activate it, and generally add a new containers icon to the toolbar, from where you can start managing them.

From that moment on, the containers will be active in your browser . The extension enables the built-in function and gives you the most important management options without you having to do anything else.

Configure and customize your first containers

When you install Multi-Account Containers, Firefox typically creates four predefined containers designed to cover the most common uses: for example, "Personal," "Work," "Banking," and "Shopping." These are a useful starting point, but you're not limited to them at all.

To adapt them to your workflow, you can edit or create new containers from the extension icon . Click the containers button in the toolbar and choose the "Manage Containers" option, where you'll see a list of all existing containers.

From that administration screen, you can change the name, color, and icon of each container to make them easy to identify. For example, you could use red for "Banking," blue for "Work," green for "Purchasing," and a different color for each specific client or project.

To create a new one, simply select the corresponding option, usually something like "Add new container" or "New container ," enter the desired name, choose the color and icon, and confirm. It will then appear in the list along with the others.

A typical use case involves creating a container with the name of your blog, your company, or a specific client to centralize all related services in one place . There you can open their Gmail, their management tools, their social media accounts, and any other website you only want to use within that context.

How to open tabs in a specific container

Once you've created your containers, the next step is to learn the most convenient way to open new tabs within a specific container . You have several options depending on your preferences and how you work with your mouse or keyboard.

A very practical method is to place the pointer over the " Open a new tab" button and right-click . This will bring up a context menu with a list of available containers, allowing you to choose which one you want to open the new tab in.

When you select a container from the menu, Firefox opens a new tab associated with that container . You'll see it colored with the shade you've set, and you'll usually also see a small label or indicator in the address bar with the container's name.

In that tab, you can go to any website you want, for example, Gmail if it's a container dedicated to your blog or work. The first time you access it, you'll have to log in because the container doesn't share cookies with others . That session will be saved only within that container.

If you then open Gmail in another container, or even outside of any container, you can log in with a different account without affecting the one you already had open. This is how you can manage multiple accounts for the same service simultaneously.

Make a site always open in its container

To further automate your workflow, the extension offers the option to associate a specific website with a particular container . This way, every time you try to access that site, Firefox will redirect you to its assigned container.

The process is simple: open the website in question within the container you want to use by default, for example, Gmail in your blog or company container . Once you're logged in and everything is working as expected, click the Multi-Account Containers extension button.

In the drop-down menu, you'll see an option similar to "Always Open This Site in…" . Clicking it will display the list of containers, and you'll need to choose the container you want to permanently associate with that specific website.

From that moment on, when you open a regular tab and type the URL of Gmail (or the website you've configured), Firefox will show you a notification indicating that the site is set to open in that container . You can check a box like "Remember my choice for this site" and confirm.

From then on, every time you access that service, the browser will automatically redirect the tab to the correct container , with your session ready and without mixing accounts or cookies with other areas of your browsing.

Force container selection for each new tab

If you're someone who constantly opens multiple tabs and wants tighter control, you can enable an option that prompts Firefox to ask you to select a container each time you open a new tab . This way, nothing will slip into the wrong container.

Normally, the default behavior is to open tabs without a container when you click the new tab button or use the keyboard shortcut. But you can change this behavior in the extension's options so that a selection menu always appears.

In the Multi-Account Containers settings, you'll find a checkbox similar to "Select a container for each new tab ." If you check it, the workflow will change: when you click the new tab button, a small panel will appear with all your containers.

When you select one, the tab will open directly within that container, with its corresponding color and settings. This is very useful if you want to maintain strict discipline and prevent websites from sneaking into the "default" container.

If at any point you prefer to return to the traditional behavior, simply uncheck that option in the extension settings , and new tabs will again open without a container unless you use the context menu or the extension icon.

Group tabs by containers and other useful features

When you've been working for a while and have a lot of tabs open, it's easy for things to get chaotic. To prevent this, the extension adds a feature to automatically sort tabs by their container.

To use it, open the Multi-Account Containers menu from its icon in the toolbar and look for an option like “Sort Tabs by Container” . When you activate it, Firefox will reorganize the tabs in the current window, placing together all those that belong to the same container.

This way, you'll have, for example, all the "Work" tabs in one place, then the "Personal" tabs, then the "Banking" tabs, and so on, without having to drag them one by one. It's a very quick way to get things back in order when you've been jumping from one topic to another.

In addition to this feature, the extension offers other settings and possibilities that, while not always explained in detail, you can gradually discover by exploring the options . Many are designed to further refine its behavior based on your habits.

It should not be forgotten that all this is in addition to the possibility of integrating containers with Mozilla VPN to protect browsing in each area , or of using additional extensions within Firefox that complement session management and security.

Firefox containers, enabled and managed through Multi-Account Containers, offer a powerful combination of organization, privacy, and convenience , especially for those who need to manage multiple digital identities without losing their minds or sacrificing their privacy.