Firefox 141 Adds On-Device AI Tab Grouping and Better Vertical Tabs

Firefox 141 lands one of Mozilla's most practical AI features yet: automatic tab grouping that runs entirely on your own machine. Combined with the vertical-tab improvements carried over from version 140, it is a strong release for anyone who keeps a wall of tabs open all day.

Key takeaways

• AI tab grouping runs locally. A small on-device model clusters similar tabs and suggests a name for each group; nothing leaves your machine.
• The feature rolls out progressively, so it may not appear the instant you update, and you can accept or reject every suggestion.
• Vertical tabs got more flexible in 140 and 141, with resizable pinned tabs and a draggable tools divider.
• Firefox 141 also brings Linux memory savings, no forced restart after package-manager updates, and native Windows 11 caption icons.

Automatic, local AI tab grouping

The standout feature in Firefox 141 is AI-powered automatic tab organization. Firefox identifies similar tabs, groups them together, and even suggests a name for each group. You can also right-click an existing group and choose Suggest more tabs for group, and Firefox will find related tabs based on their titles and descriptions.

The important detail is where this happens: everything runs locally on your device. Firefox does not ship your open tabs off to a server to analyze them. The model lives on your machine, so the privacy trade-off that usually comes with AI features is largely off the table here. The one real cost is local: the model uses some CPU and memory while it works, which is worth knowing on older or low-power laptops.

For people who routinely have 30 or 40 tabs open across shopping, research, and work, this turns an unmanageable strip into a set of sensible, labeled groups with no manual effort. If you care about keeping AI features on-device rather than in the cloud, the same philosophy drives a lot of 2026's small on-device language models.

Vertical tabs keep getting better

Firefox 140 introduced resizable vertical pinned tabs. You can drag the divider to keep more or fewer pinned tabs in view, which makes the vertical-tabs sidebar far more flexible for heavy users.

Firefox 141 builds on that. In vertical-tabs mode you can now drag the divider at the bottom of the sidebar to resize the tools area, pushing any extra tools into an overflow menu. It is a small thing, but it gives you finer control over how much of the sidebar goes to tabs versus tools.

If you have not tried vertical tabs, they pair naturally with the new AI grouping: a tall sidebar of labeled groups is much easier to scan than a cramped horizontal strip, especially on a widescreen display where vertical space is plentiful.

More from Firefox 140

Version 140 brought a few other features worth enabling:

• Custom search engines, which you can add by right-clicking a search field on a supported website or through Settings.
• The ability to unload tabs to cut Firefox's memory and CPU usage, useful on machines with limited RAM.

The tab-unloading option is especially handy alongside the new grouping. You can keep dozens of tabs organized into groups while letting Firefox quietly free the resources of the ones you are not actively using.

Platform-specific polish in 141

Firefox 141 also includes targeted improvements per operating system:

• Windows 11: the browser now uses native font icons for the window caption buttons, so the title bar looks more at home in the OS.
• Linux: reduced memory usage, and no more forced restart after a package-manager update, which removes a long-standing annoyance for Linux users.

If you are a Windows user trying to keep total memory pressure down, tab unloading here plays nicely with system-level habits, the same RAM-saving mindset behind stopping Chrome from hogging memory.

What changed across 140 and 141

If you skipped a version, here is the combined feature list and where each one lives:

Feature	Version	Where to find it
On-device AI tab grouping	141	Right-click a group, "Suggest more tabs for group"
Resizable tools divider in vertical tabs	141	Drag the divider at the bottom of the sidebar
Native Windows 11 caption icons	141	Automatic in the title bar
Linux memory savings, no forced restart	141	Automatic after a package-manager update
Resizable vertical pinned tabs	140	Drag the pinned-tabs divider in the sidebar
Custom search engines	140	Right-click a search field, or Settings
Manual tab unloading	140	Frees RAM and CPU for inactive tabs

How to get it and try the features

Firefox updates itself automatically, but you can force the check:

1. Open the menu and go to Help > About Firefox.
2. Firefox checks for and installs any available update.
3. Restart the browser when prompted.

Once you are on 141, enable vertical tabs from the sidebar settings if you have not already, and watch for the automatic grouping to start organizing your tabs. Because the AI rollout is progressive, it may take a little while to appear even after you update. You can always undo or adjust any group manually.

Frequently asked questions

Does the AI tab grouping send my tabs to Mozilla?

No. The model runs entirely on your device. Your tab titles and contents are not uploaded to a server for analysis.

Why don't I see the grouping feature after updating?

The feature rolls out progressively rather than to everyone at once. Confirm you are on 141, then give it some time; you can also manually create groups and use "Suggest more tabs for group" in the meantime.

Will on-device AI slow down my laptop?

It uses some CPU and memory while it analyzes tabs, which is most noticeable on older or low-power machines. For most modern laptops the impact is brief and minor.

Do vertical tabs require any add-on?

No. Vertical tabs are built in. Enable them from the sidebar settings; the resizable pinned tabs and tools divider come with versions 140 and 141.

Should you update?

Yes, without much hesitation. The on-device AI grouping is the kind of feature people end up relying on without thinking about it, and Mozilla implemented it in a privacy-respecting way that fits the browser's reputation. Add the vertical-tab refinements, tab unloading for memory savings, and the per-OS polish, and Firefox 141 is a meaningful upgrade for anyone who treats their browser as a workspace rather than a single window.