Sidebar and Vertical Tabs Launch in Release 136

[asafko]

Hi folks! The updated sidebar and vertical tabs are now rolled out and available to all release users on Firefox 136.

How to enable it
Go to Firefox Settings → General → Browser Layout and check Show sidebar. Then, choose the settings icon in the sidebar to customize which tools appear. You can turn on vertical tabs from sidebar settings or simply right-click on the Firefox toolbar or tab strip and select Turn on Vertical Tabs.

Firefox Settings: Browser layout

Customize sidebar options

Key improvements

✅ Horizontal tab users can now hide and show the sidebar with one click using the sidebar toolbar button.

✅ Sidebar settings have been streamlined, making customization easier.

✅ Close vertical tabs in one click without expanding them. The close button now appears when hovering over a tab favicon.

✅ We’ve removed auto-collapse behavior of vertical tabs, as it proved cumbersome for many folks. 

What’s next? 

We’re working on more improvements to enhance the sidebar and vertical tabs experience. Some top priorities include:

• Remembering your last opened sidebar panel. When you hide the sidebar and then reopen it, the last opened panel will already be expanded. We hope to ship this as soon as Firefox 137 (April 1).
• More sorting options for history and better keyboard navigation, to match the functionality of the previous sidebar version.
• Expanding vertical tabs on hover for easier navigation.

As usual, we appreciate your patience and continued use as we refine these features and experiment to help us get to a better, more polished experience. 

[Alaric]

New options are nice, but I really, really dislike the UI layout. I really just want my bookmarks on the sidebar, as I had before. But now, this update has suddenly introduced ~30% more useless wasted sidebar screen space. Why? I can remove all the other sidebar option buttons, so why do I need to see the sidebar itself just hanging out there with a single button for the only sidebar option that I want? Please, please, please let us hide the sidebar itself to reclaim this wasted screen space introduced with this new update.

This has actually driven me to make an account here and seek out a way to give this feedback here because it bothers me that much.

[JBL_in_AZ]

I have to say it.  I can't use vertical tabs as I just tried them in Firefox 138.0.1.  It's better than what I experienced when I tried it in Chrome, but not much.  I have been using the Tree Style Tab Extension for I-don't-know-how-many years.  Not only are tabs vertical, but they can be arranged in trees; you can set it to open a link in a "subordinate" tab, and you can have as many levels as you want.  If you have a tree of tabs you're not actively using, you can collapse them into a top level tree so they are out of your way.  Not quite the same as tab groups, but similar.  And there are lots of options.  This design has been around for so long I'm surprised you haven't taken advantage of it.  As long as it keeps working with the current version of Firefox (and the developer has been keeping up) I won't use anything else.  I've included snapshot of my current tabs (with some nesting) and two collapsed trees, one with 18 tabs; hovering such a tree lists lists the tabs hidden there.

[DeadKing]

Is there a way to make the bookmarks menu on the side bar floating instead of It pushing the webpage content to the side?

[dongadoya]

The bookmarks toolbar button might work for you.

[DeadKing]

Yeah I prefer that for now. But the menu in the sidebar has a search and just looks nicer.

[iodine9669]

Any plans to keep the pinned tabs styling consistent regardless of the state of the on-hover expand feature? Here's a bunch of screenshots to showcase the issue:

Expand sidebar on hover: ON

Expand sidebar on hover: OFF

[purple]

I could only use this if you bring back autohide. I need as much screen real estate as possible, especially when working on a laptop

[purple]

Also I want it so that its completely invisible until I touch the edge, just like how Zen does it.

[iesper]

Love the vertical tabs so far, but as someone with one vertical monitor, I would love to modify / set a threshold where tabs should be activated.

[davidleejy]

Firefox could consider achieving feature parity with popular vertical tab extensions like "Sidebery" (https://github.com/mbnuqw/sidebery).

What I think are possibly the four most helpful features for users managing hundreds of tabs in Firefox:

- Rename tab titles.

- Color tabs.

- Tab groups (see attached screen recording)

- Tab preview on mouse-over (see attached screen recording)

[icemessenger]

I am using both Firefox and Edge. 

Love the sidebar in Edge, so many apps like Instagram, Whatsapp, Facebook, Discord, Twitter, etc. and they can be reordered by dragging around easily. Sidebar in Opera is nice too, but far lesser apps. Chrome is the worst - no sidebar.  

Some of the issues with Firefox sidebar:

• Not all add-ons/extensions are shown on the sidebar
• No options to reorder the extensions
• Cannot hide extensions 

[tgm_1]

You guys have done a great job on the vertical tabs!

I have just one request though - with the bar on the left, tabs would be easier to close if the close button was on the left, right at the screen edge. At least, I think it would be...

[Agentvirtuel]

Hello

https://connect.mozilla.org/t5/ideas/make-closing-tabs-easier-on-sidebar-expand-on-hover/idc-p/96600
If you wish to test userChrome.css

[Shriradhakrishn]

Request to Introduce AI Sidebar in Firefox for Android

I appreciate your recent innovation in integrating an AI sidebar on Firefox desktop. I would like to request that this feature be extended to Firefox for Android as well.

Given the increasing reliance on AI tools, having an AI assistant sidebar on mobile would greatly enhance productivity and user experience. Bringing this feature to Android would reinforce Firefox’s leadership in user-focused, privacy-respecting innovation.

Thank you for considering this request.

Sincerely,
A Firefox for Android user