Firefox containers review: a separate shopping box

Firefox Multi-Account Containers is a free add-on from Mozilla for people who shop, bank, or sign in to work sites in Firefox.¹ It puts those activities in color-coded tabs so a store’s cookies stay in the shopping box.¹ A cookie is a small note a site stores so it can recognize you later. The project is open source under the Mozilla Public License 2.0 and is still being updated.²

Last checked October 28, 2026.

At a glance

• What it is: A free Firefox add-on that keeps sites in separate color-coded tabs so their cookies stay apart.
• Works on: Firefox 91.1 or later on a computer.³ Container support on Android is still an open request.⁸ Mozilla says Firefox cannot offer that same add-on ecosystem on iOS.⁹
• Price: Free.¹ Mozilla VPN for one container needs a paid subscription.⁴
• Licence: Mozilla Public License 2.0²
• Best for: Shopping, banking, or a work login you want kept apart from the rest of your Firefox tabs.
• Official site: Firefox Multi-Account Containers

What Firefox Multi-Account Containers does (and how it protects your privacy)

The add-on lets you keep parts of your online life in different tabs. Mozilla’s listing says cookies downloaded in one container are not available to the other containers.¹ You can stay signed in to two accounts on the same site, such as a work mailbox and a home mailbox, because each box keeps its own stored data.¹

That is the useful part for shopping. Tanvi Vyas wrote on the Mozilla blog that tracking cookies set in a shopping container are not available to sites in a personal container.⁶ A tracker can still follow you inside the shopping box.⁶ Linking that visit to another box takes a browser fingerprint.⁶ A fingerprint is a bundle of technical details that can identify the browser when cookies are blocked.

On 21 July 2026 Mozilla announced a preview of containers built into Firefox 153.⁵ Cookies and ad tracking stay inside each container.⁵ You can open a container tab by right-clicking a tab, long-pressing the new-tab button, or using Firefox Settings.⁵ If you already use the add-on, Mozilla says you can keep it, because the preview does not yet include every add-on feature.⁵

Key features of Firefox Multi-Account Containers

• Separate site storage. Each container has its own cookies, local storage, indexedDB, and cache.⁶ Those are the small notes, saved files, and on-device data a site can store in the browser.
• Names and colors. You can change a container’s colors, names, and icons, so a shopping box is easy to spot.¹
• A container tab from the tab bar. A long click on the new-tab button opens a container tab.¹
• Always open a shop in one box. Right-click inside a container tab to assign that site so it always opens there.⁴
• Sync between computers. Sync shares your containers and site assignments with other computers on the same account. An account is required.⁴
• Optional VPN or your own proxy. A container can use Mozilla VPN or a proxy you choose. A proxy is another computer your traffic passes through. VPN integration needs a paid subscription and extra permissions.⁴

Pros and cons of Firefox Multi-Account Containers

Pros

• Shopping cookies stay out of the containers you use for everything else.⁶
• You can hold two logins on one site at the same time.¹
• The add-on is free, and the source code is under the Mozilla Public License 2.0.¹²
• Version 8.3.8 is the current public listing. The add-on file is dated 24 June 2026, and the source repository is not archived.¹²
• Firefox 153 includes a containers preview, and the add-on can stay installed beside it.⁵

Cons

• Every container still uses the same IP address, user agent, and operating system, so fingerprinting can still link them.⁶ A user agent is the name-string the browser sends with each request. See also what your internet provider can still see.
• History is shared. A site you opened only in the shopping container can still appear in Firefox history.⁶
• Saved passwords are not kept apart. Mozilla’s containers wiki lists them as not separated on purpose.⁷
• A sign-in stored in one container is not there when you open another, so the boxes take a little practice.⁷
• It needs Firefox 91.1 or later on a computer.³ Container support on Android is still an open, unassigned request.⁸ On iOS, Mozilla says Firefox cannot offer that same add-on ecosystem.⁹

Is Firefox Multi-Account Containers safe and private?

The listing’s author is named Firefox, and the username is mozilla. The source sits in the mozilla/multi-account-containers repository, which is not archived. Its last recorded push was 16 October 2026.¹² The current listing is version 8.3.8. The add-on file was created on 24 June 2026 and asks for Firefox 91.1 or later.¹³ In that manifest, the required data-collection list is none.³

Vyas described a separate cookie jar for each context, covering cookies, indexedDB, local storage, and cache.⁶ She also wrote that history still lists a site you opened in another container, because the site cannot read your history, and that every container shares one IP address, user agent, and operating system.⁶ The project wiki lists saved passwords as not separated on purpose.⁷ BellCrier’s free fingerprint test shows how distinctive your browser looks. Turning on sync requires an account.⁴

How to get started with Firefox Multi-Account Containers

1. Install Firefox from Mozilla’s download page if you do not already use it: Firefox for desktop.
2. Open the Firefox Multi-Account Containers page and add it to Firefox.
3. Click the containers icon. Change one container’s name, color, and icon so it is clearly your shopping box.¹
4. Long-click the new-tab button and do your store browsing in that shopping container.¹
5. Right-click inside the shopping tab and assign the store so it always opens in that container.⁴
6. On a second computer, turn on sync if you want the same boxes and site assignments. You will need an account.⁴
7. On Firefox 153 you can also open a container from the browser itself: right-click a tab, long-press the new-tab button, or create one in Settings. Keep the add-on if you want the features the preview does not include yet.⁵

Who should use Firefox Multi-Account Containers (and who might prefer something else)

Use it if you browse in Firefox on a computer and want a shop, a bank, or a work login kept in its own tabs. It fits when a store’s cookies are the problem, and you still want to stay signed in next time. It also fits when one site needs two accounts open together.

On Android, Mozilla’s request for containers is still open and unassigned.⁸ On iPhone, Mozilla says Firefox cannot offer that same add-on ecosystem.⁹ For a beginner-friendly browser, see Brave. When a fingerprint is the worry, read about Mullvad Browser. Mozilla’s listing says a container can use Mozilla VPN to protect browsing and location, and that needs a paid subscription.¹⁴

Frequently asked questions

Is Firefox Multi-Account Containers free?

Yes. The add-on listing does not require payment.¹ The source code is under the Mozilla Public License 2.0.² Using Mozilla VPN for a container needs a paid subscription and extra permissions.⁴

Is Firefox Multi-Account Containers safe?

Cookies and other site storage stay in the container that saved them.⁶ The IP address stays the same across boxes, so fingerprinting can still connect them.⁶ The manifest lists required data collection as none.³

Does Firefox Multi-Account Containers work on Android or iPhone?

Use it in Firefox 91.1 or later on a computer.³ Mozilla’s bug for container support on Android is still marked new, with nobody assigned.⁸ On iPhone, Mozilla says Firefox cannot offer that same add-on ecosystem.⁹

Does Firefox already include containers?

Firefox 153 includes a containers preview, with names, colors, and icons you can set in the browser.⁵ Mozilla says that preview does not yet have every Multi-Account Containers feature, and you can keep the add-on installed next to it.⁵

Sources

1. Mozilla Add-ons: Firefox Multi-Account Containers
2. GitHub: mozilla/multi-account-containers
3. Mozilla: Multi-Account Containers manifest 8.3.8
4. Mozilla: Multi-Account Containers English strings
5. Mozilla Blog: Introducing Native Containers in Firefox 153
6. Tanvi Vyas: Contextual Identities on the Web
7. MozillaWiki: Security/Contextual Identity Project/Containers
8. Bugzilla: 1807456 Support for containers
9. Mozilla Open Policy and Advocacy: Browsers compete on privacy. When the operating system allows.