The new Firefox design lands in today. This is what you can expect

[AshleyT]

Firefox has evolved significantly over the past year and now, its look has evolved too. 

The design begins rolling out today, with Firefox 157, bringing a cleaner, more cohesive , and more adaptable experience. It is still the Firefox you know and trust, with the same commitment to independence, privacy, customization, and user control. 

The Mozilla Connect community has helped shape this work from the beginning by sharing feedback on the early designs, tested the experience in Nightly starting in July, filed bugs, and shared with us what worked and what didn’t.

Here’s what landed today.

A cleaner, more cohesive design

• Softer tab shapes
• Redrawn icons that hold up better across light and dark themes
• Rebalanced spacing throughout the interface
• A refreshed color palette featuring the glow of the active tab, deeper purples, and warmer light tones

The updated design brought bolder color choices to Firefox — and your feedback made clear that opinions on browser color run the full spectrum. In response, we created additional themes, accessible through add-ons and a new theme picker off Firefox Home, so you have greater control over how Firefox looks. 

More ways to make Firefox yours

Firefox is becoming more customizable, giving you more ways to shape the browser around how you browse. These options include:

• A new theme picker in the customization panel on the Firefox Home page. Additional community themes remain available through about:addons.
• New Firefox themes and wallpapers
• A dedicated space to pin and organize shortcuts so sites you use all the time stay put.
• Compact Mode for a denser browsing experience

Compact mode now officially supported!

Compact Mode is now available as its own dedicated setting. It will also switch on automatically on smaller screens, reducing the space between interface elements so more fits on the screen.

This is one of the clearest examples of how community feedback shaped Nova. Many of you told us that maintaining a denser interface was important, and we listened.

Faster performance

The refreshed experience also includes improvements to Firefox’s startup, page-loading, and scrolling speeds.

Frequently asked questions

Will my existing themes and add-ons continue to work?

Themes and add-ons should continue to work. Nova is built on the same Firefox foundation, and the extension and theming architecture has not changed.

Will my userChrome.css customizations continue to work?

Some customizations may require minor adjustments, depending on how closely they rely on element names or layout structures from the previous interface. 

But keep in mind that Mozilla does not officially support customizations made through userChrome.css. They can cause unexpected behavior or even break Firefox, and future updates may affect them as Firefox continues to evolve. If you choose to use userChrome.css, please proceed carefully.

You can learn more in Firefox advanced customization and configuration options.

Can I opt out of the update?

The new Firefox design becomes the default experience starting with Firefox 157. However, you have several ways to adjust how Firefox looks and feels, including Compact Mode, themes, wallpapers, and New Tab customization. 

Keep shaping Firefox with us

Nova may be shipping today, but the work doesn’t stop here. Many of these updates grew directly from the bugs you filed and the conversations you started while the design was being developed.

Update to Firefox 157 to try the refreshed experience, then let us know what works well and what could still be improved. Your feedback will continue to help shape what comes next.

[dftf]

You can revert it for now, yes.

They are proposing to stop that as of Firefox v161, due for release November 24
https://bugzilla.mozilla.org/show_bug.cgi?id=2071454 

[J35VKRYZPO]

about:config > browser.nova.enabled = "false".

[SteffenGL]

Please please dont change the layout without the users CONCENT !
I dont like the new layout and i've been looking for a way to change it back for 30 minutes now and I just cant change it back.
What on EARTH were you thinking !?!

[dftf]

No offense but...

"... i've been looking for a way to change it back for 30 minutes now and I just cant change it back."

---

Insert "you serious" meme here.

Like the solution has been posted on this forum probably like 100 times already.
And around 20-30 times on r/Firefox on Reddit, also.

Here you go (though in future, try scrolling and read some existing comments):

In the URL bar type about:config then press ENTER
Accept the warning and continue
Search in the box for nova
Double-click the line "browser.nova.enabled" to set it to "false"

[SteffenGL]

Sorry dftf, but the feedback section was the last place i went to look for a solution. I tried googling the web and looking for a youtube tutorial first.

Either way, why do i have to waste my time setting firefox back to the default state that i have been enjoying for years. It's a total waste of my time.

But yes, once i scrolled down 20 posts i found your post and it solved my issue - so thank you

[Cheek]

Seems a shame to mess around with stuff in a way that makes my set-up actively worse, mostly by badly duplicating the excellent function of Tree Style Tab. I've had to dig around to try to find out how to hide the native sidebar and tabs, and even after that, I've lost screen width that was previously in use.

Generally, meh.

[Geez]

Nova looks genuinely awful and ugly as fk. The old tabs were cleaner, sharper, easier to read, and much better suited to a desktop browser. The new design feels oversized, cartoonish, and like a mobile interface forced onto a PC.
It honestly feels like your design team has nothing useful left to do, so you keep inventing work for yourselves just to justify your jobs by changing and ruining parts of Firefox that were already perfectly fine. These new rounded tabs are ugly, unnecessary, and make the browser look worse. Please stop redesigning things just for the sake of change and leave the old tab design alone.
about:config > browser.nova.enabled = "false".

[DragomirSan]

I just want to say that I like the new UI and I also see an improvement in speed, it feels snappier. 

(v157, Windows 11, Light mode, vertical tab list)

I know that you don't get a lot of comments with positive feedback 🙂

[leojth]

Sorry, but I want square tabs. I've used Firefox since version 1 and this is actually one of the reasons I kept using Firefox over the years. Luckily I could turn Nova off.

[dftf]

You can turn it off for now, yes.

They are proposing to stop users from doing so in Firefox v161, expected Nov 24, 2026:
https://bugzilla.mozilla.org/show_bug.cgi?id=2071454 

[rw335i]

Once v160 is loaded I will block all updates.

[dftf]

You'd be better-off switching to the 153.x ESR version:
https://www.firefox.com/download/all/desktop-esr/

That is before the 157.0 UI changes, but the ESR versions get security-updates
for around a year after release.  So it'll be safe to use for a while yet.

Backup your current data from 157.0 via:
Menu > Settings > Accounts and Synchronisation > Backup

Uninstall 157.0, reboot, install the ESR release, then start it

Get your data back:
Menu > Settings > Accounts and Synchronisation > Restore your data...

[m-fessler]

Congratulations, a new design is exactly what Firefox was missing.
With rounded tabs and buttons complete and gradients, it's only a matter of days before Chrome is overtaken!

Seriously, Mozilla, what are you thinking?
Why not invest the time and money in more important areas instead of keeping the design department busy?

Or at least leave the Proton theme and the "browser.nova.enabled" switch in place until the next major design overhaul (how about square tabs again for a change?)!

Martin
... a Firefox user since day one - let's see how much longer that lasts.

[NotCool]

You guys this update is bad bad, like real bad. Like I know some of you have been saying it and some other team is pushing it. We all know how it goes... But there are no positive posts about the look, about the UI. It is okay to make changes, it is okay to improve, but whatever guidance got you here has NOBODY praising it. That means you have to reassess how you got here MORE importantly than reverting or fixing it. That part is easy, revert the UI/Nova "Sorry we got it wrong you didn't want that so we restored classic look and have the updated UI available as well."

But what went wrong to allow this all the way through? What mechanisms are not working on feedback, who has too much control to lead the whole team so astray? This is a monumental failure in the swiss cheese model - that is what needs your most attention. The revert on the UI is simple, just do not delay.

[privacyname]

The new rounded look is terrible. Return squared theme immediately !!!! 

[dftf]

Return the square tabs:
URL bar -> about:config -> ENTER -> accept warning -> search nova ->
double-click line "browser.nova.enabled" to change to "false"

Install the previous theme from here:
https://addons.mozilla.org/firefox/addon/firefox-proton/ 

⚠ The ability to reverse Nova may end in Firefox v161, expected Nov 24, 2026
https://bugzilla.mozilla.org/show_bug.cgi?id=2071454 

[rw335i]

The proton theme is not quite the same as what I have now. For one thing I have blue in the top area rather than the gray you get with proton. A minor thing but still an irritation.

[dftf]

Take a look at all official themes from Mozilla; maybe you'll find the one you want?
https://addons.mozilla.org/firefox/search/?promoted=line&type=statictheme

Alternatively, install this add-on:
https://addons.mozilla.org/firefox/addon/firefox-color/ 

Then you can make your own theme here:
https://color.firefox.com/ 

[asdf_]

This is terrible. Please disable it by default.

[asdf_]

This should be an opt-in at first launch and an easy setting, not hidden behind a flag. As soon as I saw this, I looked for `browser.nova.enabled` and turned it off. This is truly hideous.

[crc79]

The update was pushed to my computer today and after seeing the new design the first thing I did was search for how to switch back to the old design. (browser.nova.enabled = false) Then I searched for how to give feedback about it. 

Please stop changing stuff that does not need changing. My browser doesn't need to be fancy. I use it to look at web pages. It doesn't need to try to distract me from that task.

[Jekiro]

I joined the discussion just to express my disappointment in the recent design update, it's nice. But I wanted the history to be cleared when grouped by date, right click on it and just press delete. It was easy and convenient, i use Firefox because it was the most comfortable browser i have used.

Bring back the way it is.

[KP2]

Hi, is there an easy way to disable oval shapes of tabs and go back to the good old rectangular ones? The oval ones give me big discomfort when using. I do not want to move to another browser bacause of that. Thank you.

[anotherBob]

about:config, search for "nova" and set browser.nova.enabled = false

[KP2]

Thanks, brother!

[mlwasteland]

Agreed.

[mercurie80]

Is there any way we can have the square tabs back? I really don't like the rounded tabs. 

[dftf]

Restore square tabs by:

1. In the URL bar type about:config then press ENTER
2. Accept any warning shown
3. In the search-box, type nova
4. Double-click the line "browser.nova.enabled" to change it to "false"

You can also get the previous theme here:

https://addons.mozilla.org/firefox/addon/firefox-proton/ 

[SkipJacobson]

Rounded tab corners looks awful and impacts functionality, I've had so many issues trying to X out of a tab today that I finally went into the config and disabled the Nova update. Horrendous. I've already been slowly migrating a decade's worth of bookmarks over to a different browser since the ai stuff started being added, with the kill switch only mollifying me slightly, but this behavior sped up my migration significantly. I'm not gonna yell at the receptionists since I'm betting this change was from the higher ups, but my god this is an unwanted update.

[mlwasteland]

agreed.

[katzen]

This is vile. PLEASE let me disable rounded corners. I just want SQUARE EDGES. This redesign is making me want to leave Firefox entirely and ruins the trust I had in Mozilla's design sense.

[AstrobotNautics]

See dftf's replies further up, or this thread here:
https://connect.mozilla.org/t5/discussions/bring-back-rectangular-tabs/m-p/140846#M57393

This disables it without add ons. 

URL= about:config, search for nova, set "browser.nova.enabled" double-click to "false"

[anjimoo]

This redesign is shockingly bad in every single way I can think of. It's ugly, difficult to read, distracting, space-inefficient and generally annoying. I miss the good-looking and usable UI. Please revert this mistake.

[dftf]

URL bar -> about:config -> ENTER -> accept warning -> search nova ->
double-click line "browser.nova.enabled" to change to "false"

That should undo most of it.  Then get the previous theme back by installing this:

https://addons.mozilla.org/firefox/addon/firefox-proton/ 

[Sweet_Hina]

Oh my gosh! Since the update, anything I use or look up on the browser works slowly than ever. Put it back to the way it was! I don't care about look or design. We live in a fast pace world. And I expect the browser to work even faster. Not "look cool." This is technology. Not a fashion show.

[dftf]

The new theme really shouldn't make your browser slower: that's likely an extension causing that issue.

First undo the new theme changes with these steps:

In the URL bar, type about:config then press ENTER
Accept any warning
Search for nova
Double-click the line "browser.nova.enabled" to change it to "false"

Then check for updates for your extensions:

Menu -> Extensions and Themes -> ⚙ -> Check for Updates

If you still have issues on specific sites, an extension you use that does ad-blocking or
script-blocking may be causing an issue on that site (e.g. Ghostery, AdGuard, uBlock).
Try disabling it on that page

[Junior0]

The rounded corners are garbage like the apple things. Please just make a switch to rectangle in the tabs and buttons or I will need to make a downgrade, even if its not a good idea for security reasons. Its terrible to use this "pilula" design or start to looking for another browser. 

[dftf]

For now at least it's possible to reverse most of it:

URL bar -> about:config -> ENTER -> accept warning -> search nova ->
double-click line "browser.nova.enabled" to change to "false"

You can also get the previous theme here:

https://addons.mozilla.org/firefox/addon/firefox-proton/ 

[Mittens]

Horrible UI and a total waste of time and resources in yet another update following in the footsteps of the Discord design team, this totally useless Nova experiment is just furthering the exodus from this out of touch organisation

[dftf]

To mostly-reverse the recent change:

URL bar -> about:config -> ENTER -> accept warning -> search nova ->
double-click line "browser.nova.enabled" to change to "false"

If you want the previous themes, install this:

https://addons.mozilla.org/firefox/addon/firefox-proton/