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.

[JNavas]

You've completely mischaracterized my posts with red herrings and misstatements that reflect your obvious misunderstanding of enterprise software engineering. But your insulting tone ends the discussion. We'll just have to agree to disagree.

[cadwellm]

Thank you for the conversation. Ultimately, I'm just glad a detailed breakdown of how forks operate was laid out in the open so fellow users have the info they need to make an informed choice. Take care!

[medin]

This new design looks not professional, too much round corners and round buttons, it feels like it was done by a kid loving round shapes.

[maiconandsilva]

I liked the icons theme but these rounded corners are too much. It was perct before 🥲 Why is it copying Google Chrome? Chrome is ugly!!

Another thing I dont like is the shadow on hover and on select. Seems so simplistic now. Idk what changed.

[Vyrtsev]

Can we make borders even more round, like up to 11. Maybe 1000px?

[JNavas]

Version 153.5.1, first offered to ESR channel users on October 20, 2026
I confirm this release retains the user-preferred Proton UI style.

[jammnrose]

Hate the overly rounded everything and new theme. Looks like a garbage AI slop written Chrome copy.

Disabled immediately. browser.nova.enabled -> false

[Agentvirtuel]

Bonjour

A similar discussion thread https://connect.mozilla.org/t5/discussions/just-allow-people-to-disable-nova-on-settings-gt-appearan...

[Ilya__]

Please add an option to roll back to the previous version. Your new design is consuming an excessive amount of CPU resources and 3 GB of RAM with only 5 tabs open; previously, it worked fine even with 20 tabs.

[dftf]

It may be a particular website causing this, or an extension.

Try going to Menu -> More tools -> Task Manager.
Then click on the "Memory" column, to sort largest-first.

If a particular website is causing the high RAM, it might have an issue in Firefox.
You can use Menu -> Help and Report -> Report Broken Site to let them know.

However, it's worth first seeing if an extension is causing the issue.
Load the site in Menu -> Help and Report -> Troubleshoot Mode.
If it doesn't use high RAM there, an extension you use is causing the page to break usually.

If you can't solve the issue, you could also consider dropping-back to the 153.5.1 'ESR' release,
which may help.  You can even install it alongside the current 158.0.1 release, if you pick a different
folder during the install (e.g. change \Mozilla Firefox\ to \Mozilla Firefox ESR\ ).  Download it here:
https://www.firefox.com/download/all/desktop-esr/ 

[Agentvirtuel]

Bonjour

To complement, this discussion thread, this discusssion thread https://connect.mozilla.org/t5/discussions/the-new-firefox-design-lands-in-today-this-is-what-you-ca... Dedicated profiles per Firefox installation https://support.mozilla.org/en-US/kb/dedicated-profiles-firefox-installation Some users have multiple installations of Firefox, each in separate program folders. Firefox uses a dedicated profile for each installation of Firefox, including Nightly, Beta, Developer Edition and Extended Support Release (ESR) installations. This makes Firefox more stable when switching between installations on the same computer, and also allows you to run different Firefox installations at the same time.

This is my case, Firefox est à jour.

[JNavas]

• PHP Foundation 'Under-Funded' With One Full-Time Staff Member, Director Says | Reuters
  - Funding comes from donations and grants   
  - AI-related increase in coding has doubled foundation's workload   

The PHP crisis is a reality check on browser forks. Firefox is 20+ million lines of complex C++ and Rust code that processes hostile web content every second. If an industry-critical foundation cannot afford adequate engineering bandwidth, expecting volunteer-run forks to safely audit, rebase, and secure massive browser codebases is unrealistic. Public code on GitHub does not replace dedicated enterprise maintenance infrastructure.

[cadwellm]

Correction, the PHP crisis is a reality check for ALL browsers INCLUDING forks.

[JNavas]

---

@cadwellm wrote:
Correction, the PHP crisis is a reality check for ALL browsers INCLUDING forks.

---

Yes, the PHP crisis affects all Web access, not just browsers of any kind.

But the PHP crisis isn't about which app accesses the Web; it's a reality check on the greatly increased risk of inadequate maintenance resources.

• Mainstream browsers have dedicated full-time security teams and extensive testing resources.
• Volunteer forks operate on thin resources with limited test infrastructure.

Conflating the two is false equivalency.

[cadwellm]

Good thing I wasn't conflating the two then. I was just taking your comment about it affecting forks and applying it to all browsers.

[dftf]

@cadwellm : ironically, there's been two security issues recently: the PHP one (more serious) and the eMudhra certificate leak (slightly-less serious, especially if you don't regularly visit uncommon websites or download random apps).

But for the latter, the 115 ESR release of Firefox (aimed at Windows 7 and 8 users, and macOS 10.12 to 10.14), as-of-now is still shipping with the certificates from that company which have since been revoked (and indeed, in the latest Firefox and the latest ESR, 153.6.0, have been).

Now, true, the 115 ESR probably gets little-attention from Mozilla now -- but for as long as they are going to make it available, security stuff like this needs backporting too.  If a major company isn't prepared to ensure all currently-supported versions of their browser are safe, then they should retire the 115 ESR branch.

And @Agentvirtuel advised me of this fork of Firefox, that works on Windows 8, 7 and Vista:
https://eclipse.cx/projects/r3dfox 

That project is backporting the 153 ESR branch back to those systems -- currently the 153.3 release is the code being used, but once they get to the 153.5.1 code or later, then the breached certificates will be removed from their code also.  Meaning then, users on Windows 8, 7 and Vista will actually not have the affected certificates by using this fork, whereas currently they still do in Mozilla's latest official offering! 🙃

[Agentvirtuel]

Bonsoir

To complement, a discussion thread, https://connect.mozilla.org/t5/firefox-labs/webseite-sein-monaten-nicht-erreichbar/m-p/145474/highli...

[dftf]

Can't wait for @Agentvirtuel 's next reply.  The usual:

"Anyway, Firefox 115 is out of date"

They're not a bot though, even though you get the same stock replies 😉

[Agentvirtuel]

Que sera, sera,
Whatever will be, will be;
The future's not ours to see.
Que sera, sera,
What will be, will be.

If i notice other cases (e.g) https://connect.mozilla.org/t5/discussions/how-can-i-stop-your-bleep-ing-update/m-p/145409/highlight..., https://support.mozilla.org/en-US/questions/1614398#answer-1859111

[Agentvirtuel]

A related discussion https://connect.mozilla.org/t5/discussions/updated-to-firefox-115-15esr-chatgpt-and-dall-e-no-longer...
https://connect.mozilla.org/t5/firefox-labs/webseite-sein-monaten-nicht-erreichbar/m-p/145485/highli..., have you tested, Eclipse r3dfox.

SSL Report: Overall Rating F, Revocation status Revoked INSECURE, at the moment, analyzed.
https://www.ssllabs.com/ssltest/analyze.html?d=www.udyamregistration.gov.in

[MarshWiggle]

I got two emails about this, from a non-replyable address that wasn't so labelled. Apparently the changes to settings are so extensive as to require a warning to users, using every email address mozilla has on record as a firefox user. 

This is why I never update firefox, in spite of mozilla's best efforts to force weekly updates, any one of which could turn out to be a denial of service attack, either in the form of user interface changes or outright bugs.

Some of your users don't appreciate churn, and only stick with you because of privacy concerns and similar. (I.e. they refuse to use Chrome or its derivatives.) 

FWIW, I don't know how to try out this update and determine whether I like it, while preserving the option to go back to the version I have now. And while I'm mildly curious, I certainly don't care enough to do the research to find out how to try it out without risk. 

[JNavas]

---

@MarshWiggle wrote:

FWIW, I don't know how to try out this update and determine whether I like it, while preserving the option to go back to the version I have now. And while I'm mildly curious, I certainly don't care enough to do the research to find out how to try it out without risk. 

---

You can create a new Profile for the new version, 
which preserves your current Profile should you decide to revert. 

1. close Firefox
2. copy the entire profile folder to a new location
3. use the copy with the newer version
4. keep the original untouched as your fallback

[MarshWiggle]

While I'm ranting: your bookmarks UI is unusable given the quantity of bookmarks I have, and adding shortcuts, however organized, doesn't constitute a fix.

You are not alone in this; last time I checked, all your competitors used the same inadequate drag-and-drop UI, and nobody supports syncing bookmarks with competing browsers. 

I've resorted to a local-to-me web page, maintained using a text editor. Yes, it's better than what you supply, at least for anyone who can read and write html, and use a text editor. 

If you must revamp things, you might consider revamping something like this that's already broken. But OTOH, a UI that would work for me would probably be regarded as horrible and useless by someone with only a handful of bookmarks (less than 100). 

[JNavas]

---

@MarshWiggle wrote:

While I'm ranting: your bookmarks UI is unusable given the quantity of bookmarks I have, and adding shortcuts, however organized, doesn't constitute a fix.

You are not alone in this; last time I checked, all your competitors used the same inadequate drag-and-drop UI, and nobody supports syncing bookmarks with competing browsers. 

---

There are a number of ways to organize bookmarks in Firefox and other major browsers:

1. Search for bookmarks of interest, select, then move or cut & paste.
2. Sort bookmarks into various orders, select, then move or cut & paste.
3. Firefox supports both automatic and manual bookmark Tags, which can be quite useful.

Chrome and Edge can both import directly from Firefox when Firefox is installed on the same computer. Firefox also supports importing from other installed browsers the same way.

[MarshWiggle]

At last count, I had 2842 bookmarks. Drag and drop simply doesn't cut it. I hadn't noticed that cut-n-paste had become available for bookmarks in web browsers. (Thanks for telling me about that.) That's effectively what I use, when editing my bookmarks with a generic text editor. (Good thing I can read and write basic html.) 

I have a requirement to access the same bookmarks from multiple different browsers, and ideally to add new ones whichever browser I'm using at the time. Importing when I install a new browser isn't good enough.

Firefox only supports syncing among firefox browsers. Chrome has the same feature, and a history of turning it on when users _don't_ want it, if they log in to Google on multiple Chrome instances. Safari can also sync multiple Safari instances.

There was a product named xmark (maybe xmarks) that could sync bookmarks among all 3 of those browsers, and probably others too. Lastpass bought the company and killed the product. 

Fortunately (?) I'd already pretty much broken xmarks. It turns out they didn't like bookmark hierarchies having multiple folders with the same name at different places in the hierarchy. They also choked badly when Chrome synchronized bookmarks at the same time that xmarks was syncing them. Cleaning up the resulting corrupted bookmark files was slow and painful. 

So now I have a web page containing my bookmarks, source controlled in git. 

[JNavas]

---

@MarshWiggle wrote:

I have a requirement to access the same bookmarks from multiple different browsers, and ideally to add new ones whichever browser I'm using at the time. Importing when I install a new browser isn't good enough.

Firefox only supports syncing among firefox browsers. Chrome has the same feature, and a history of turning it on when users _don't_ want it, if they log in to Google on multiple Chrome instances. Safari can also sync multiple Safari instances.

There was a product named xmark (maybe xmarks) that could sync bookmarks among all 3 of those browsers, and probably others too. Lastpass bought the company and killed the product. 

---

Xmarks Sync alternatives:

• Cross-Browser Bookmarks Syncing - Floccus Bookmarks Sync
• xBrowserSync - Browser Syncing as It Should Be: Secure, Anonymous and Free!

There are others if these do not fit your use case.
 

[workingjubilee]

Hello. Thank you for making Firefox. I have found what appears to be a missed consideration in the UI update, which might recommend a more serious way to adjust the way tabs look.

It feels like the ellipsoid or squircle-y look of the tabs were not tested with the Mozilla-provided-and-recommended Multi-Account Containers extension, because it looks awful with them. The ellipsoid tabs change the "which container is this?" bars on each tab to be significantly narrower than the tab's other UI elements, which breaks the visual uniformity they previously had, aligning the indicator bar to the start of each icon and ending at the text.

The "squircles", in general, are too severe on the "circle" part, as indicated by my referring to them as an ellipsoid... they simply shouldn't be that... and I'd rather they were more squared.

This is especially important because the current UI is highly misleading: when you hover your mouse pointer over a space that is on neither the tab to the left of it nor to the right of it, according to the squircle's edge, you see one of the tabs get highlighted. This is because Firefox correctly identifies the actual click-target here is a rectangle's boundary, and shows that one of the tabs is "under" the mouse pointer, even though the mouse pointer is not hovering over the squircle's area at all. This is not what should result, and it should not be easily achievable with a human guiding a mouse to get this result.

Note that these two distinct-seeming problems are the same problem: the squircle's steep curves break expectation, uniformity, and naturalness of perceiving a tab, while not actually representing the truth about the UI and its click or touch targets

I appreciate the work that human beings like UI designers do.

[Agentvirtuel]

Bonsoir

Is it this similar subject
https://connect.mozilla.org/t5/discussions/make-close-tabs-easier-for-rounded-tabs-x-on-mouseover/td...

Below, just to see, a test with userChrome.css

[JNavas]

The best solution to the ugly, less functional Nova UI (at least for the next year) is to switch from regular Firefox to Firefox ESR (Extended Support Release), which retains the classic Proton UI and is also more stable. See Navas' Tips: Firefox UI Debacle

[Agentvirtuel]

Bonjour

Firefox release notes
https://www.firefox.com/en-US/releases

Firefox 159.0 est à jour et Firefox 153.6.0esr est à jour.

On the left Firefox 159.0, clarification : i'm not a fan the Nova Style. I use, css. Among others css.

[JNavas]

> Version 153.6.0, first offered to ESR channel users on October 27, 2026

I confirm that Firefox ESR 153.6.0 retains the classic Proton UI style, not the ugly and less functional Nova.

[MarshWiggle]

Thank you for the reminder about the Firefox ESR. It's past time I switch from an elderly version of the regular firefox to a version that just might get security fixes without other churn.

[dftf]

You can move onto the 153 ESR and get security-only updates until at-least September 7th next year; after which you'll be in-place upgraded to the newest ESR at that time (planned to be 175.6).

[Agentvirtuel]

Bonjour

This discussion thread
https://support.mozilla.org/en-US/questions/1610048

On the left, browser.nova.enabled, default value, true Firefox 159.0, clarification : i'm not a fan the Nova Style. I use, css. Among others css.
On the right, just to see, browser.nova.enabled, value, true Firefox 153.6.0esr.

[MarshWiggle]

I'm back, with just ONE comment on the redesign. I've now received three emails about the changes to settings, sent to two different email addresses. The first lot arrived on Sunday; the next one arrived today (Tuesday). 

The content is basically identical, and constitute an advertisement. It appears that it will be easier for me to find things in an unfamiliar arrangement, rather than one I know (and don't especially like, TBH). 

There's a link to https://blog.mozilla.org/en/firefox/new-firefox-design/?utm_source=braze&utm_campaign=settings-notic... - notice the tracking suffixes, presumably intended to tell them that repeated emails are a great idea. 

AFAICT, the content is the same as with the bare URL https://blog.mozilla.org/en/firefox/new-firefox-design/ which is of course less likely to trigger user's concern about privacy etc.

I think my first click on that link may have taken me to a subsection devoted to describing the changes, though perhaps not the specific changes to settings, but subsequent clicks launch a new page at the top. 

The information I gather from this TLDR is that the changes are wonderful, and only a grumpy evildoer would possibly fail to see Emperor' Mozilla's New Clothes. There may be some documentation in here, or information about the specific changes to settings, but I've so far been unable to find it. 

The Yours to Shape section has a somewhat triggering name, given that the whole point of this and other updates is to give your users changes most of us never asked for, forcing us to relearn how to use a web browser for anything more complex than viewing a single page. Firefox is notoriously bad about burying its settings in numerous separate sections, often involving knowing and typing a pseudo-URL that's not accessible from its "settings" button. If there's detailed, useful documentation from Mozilla, I've never found it. 

I suspect your boasts of attention to accessibility will turn out to be dead letters, at least for me. I have a type of visual agnosia that interferes with me learning and recognizing icons. So the move to give everyone the same UI on desktops as on cell phones has been one long exercise in frustration for me. There's no room for text on a cell phone, so why show it on a desktop?! 

Overall receiving yet another email has taken my attitude from "grumble, another upgrade, grumble" to "expletive expletive expletive". At least include new content, and links to usable documentation. 

For now, I'm waiting till the new UI has been out long enough that search engines and LLM bots default to answers based on the new UI, which won't happen till Mozilla volunteers on the support site and random reditters decode the UI well enough to answer the same questions I'm going to have.  I cannot, after all, recall a recent instance where I've been able to figure out anything in Firefox using only Mozilla-provided resources. 

[JNavas]

Installing Firefox ESR on Ubuntu (Without Snap)

[MarshWiggle]

Thank you!

This looks a lot simpler than the method on Mozilla's web site, which in any case didn't work for me. I hope it's not necessary to delete the snap before installing the deb, as I'd want to keep a window with the instructions while doing this. 

[MarshWiggle]

Beware! These instructions give you a symlink in /usr/bin that's named firefox-esr.

/usr/bin/firefox continues to be a script that launches the version from the snap. 

Also, while the tar.xz I downloaded earlier but did not install claimed to be version 153.6.0 esr, firefox-esr --version reports "Mozilla Firefox 140.17.0esr"

[JNavas]

Thank you for the follow-ups.

ESR 140 is the prior ESR version.

[bennett]

I like this New Firefox Creativity