topic Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself. in Discussions

Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

brainetree — Sun, 16 Nov 2025 06:24:17 GMT

Is the rounded corners inside Firefox something new? Got rid of them in Windows 11 like a lot of people do and keep them square again after updates and here you betray me. LOL.

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

Agentvirtuel — Sun, 16 Nov 2025 06:36:55 GMT

Hello

A subject.
https://www.reddit.com/r/FirefoxCSS/comments/1ov0806/does_anyone_know_how_we_can_unround_our_tabs

And, for information purposes.
https://support.mozilla.org/en-US/questions/1546836#answer-1778873

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

brainetree — Wed, 11 Feb 2026 18:48:11 GMT

The dreaded rounded corners are back, what a burden to have to research and find out how to disable it. Why don't you just give us that option? I can not accept the rounded corners AT ALL. Thank you for listening. I have a lot of other things on my mind, but have to spend no telling how long to figure out how to get rid of those rounded corners.

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

Agentvirtuel — Wed, 11 Feb 2026 20:50:43 GMT

Hello

Have you tested.

/* In userChrome.css */ :root { --border-radius-medium: var(--border-radius-small, 4px) !important; }

Have you tested.

/* In userContent.css */ @-moz-document url-prefix("about:"), url-prefix("chrome:") { /* Firefox pages like settings etc. */ :root { --border-radius-medium: var(--border-radius-small, 4px) !important; } }

Have you tested, userChrome.css and userContent.css, together.

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

brainetree — Thu, 12 Feb 2026 23:32:11 GMT

Yes Agentvirtuel, I tried those possibilities just as you suggest and they finally worked! Thank you, what a joy and relief!

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

Agentvirtuel — Thu, 12 Feb 2026 11:55:54 GMT

Hello

For my part, tested.
https://www.youtube.com/watch?v=iEmaI4ciUFM

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

kailasanathan_k — Tue, 03 Mar 2026 08:58:49 GMT

Wait, Does these works in Android?

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

reukiodo — Mon, 14 Sep 2026 16:07:47 GMT

about:config > toolkit.legacyUserProfileCustomizations.stylesheets > true

about:support > Profile Folder > Open Folder > mkdir "chrome" > edit userChrome.css

/* Force square corners on all Firefox UI elements */ * { border-radius: 0px !important; }

tested on FF 156 and 157

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

Agentvirtuel — Mon, 14 Sep 2026 17:52:14 GMT

Bonsoir

Take Project Nova for a spin in Nightly!
https://connect.mozilla.org/t5/discussions/take-project-nova-for-a-spin-in-nightly/td-p/131273

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

reukiodo — Tue, 22 Sep 2026 14:22:02 GMT

Project nova is the reason I searched for removing the rounded corners. It looks like Apple's silly UI instead of the clean crisp UI Firefox used to have.

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

upset_ff_oldman — Tue, 29 Sep 2026 19:50:43 GMT

The solution is NOT the answer and this is fing stupid. You want people NOT to use firefox? This is the way.

The real fix is to type about:config and type nova and disable all the garbage.

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

upset_ff_oldman — Tue, 29 Sep 2026 19:52:10 GMT

NOT A SOLUTION.

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

Frozen_Baguette — Tue, 29 Sep 2026 21:16:53 GMT

I love you man, this is exactly what I wanted.

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

BushMaster69 — Wed, 30 Sep 2026 19:47:19 GMT

YES! PROBLEM SOLVED!!

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

joanofxyz — Thu, 01 Oct 2026 11:08:10 GMT

this is the real answer

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

joanofxyz — Thu, 01 Oct 2026 11:09:12 GMT

this is a horrible answer, I should not have to enable legacy features to disable something when there's a better way to do it

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

joanofxyz — Thu, 01 Oct 2026 11:10:29 GMT

absolutely not and I take offense that instead of recommending disabling this program entirely you would suggest enabling legacy styling features that will likely break next time there's an update to this "project"

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

sam_stoe — Thu, 01 Oct 2026 19:39:40 GMT

what is this solution? ..a theme or a toogle option should be a solution!

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

z0rro37 — Thu, 01 Oct 2026 20:01:41 GMT

Thank you. The CSS solutions only solve the tab buttons, but disabling nova works everywhere.

Disabling browser.nova.enabled was enough. I'll check if disabling the other options is necessary.

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

Kstf — Sat, 03 Oct 2026 04:58:02 GMT

The only good answer.

Thank you for the solution

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

Agentvirtuel — Sat, 03 Oct 2026 06:41:47 GMT

Bonjour

For information
https://support.mozilla.org/en-US/kb/contributors-guide-firefox-advanced-customization
What do users need to know before they use userChrome.css customization?

My answer, replied on 12-02-2026 03:55 AM on Firefox 145.
(e.g.) 7 months ago on Firefox Nightly https://www.youtube.com/watch?v=iEmaI4ciUFM

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

Jibun-no-Kage — Sat, 03 Oct 2026 13:27:05 GMT

HATE, HATE, HATE the new FireFox theme, look, HATE, HATE, HATE, IT. And you don't even give users a way to disable it with ease... IDIOTS.

And browser.nova.enabled is not working for some reason on my firefox. (Windows 11 PC).

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

Simon_M — Sat, 03 Oct 2026 20:31:26 GMT

I don't firefoxing understand what the firefox does a user have in their mind to accept as "solution" having to mess with custom user firefoxing stylesheets!

Of course ideally it's Firefox Engineering Managers and Product Owners responsibility to not have foreseen that an option to toggle this firefoxing rounded corners off would be mandatory, but at least they should have pushed this as an experiment to a subset of trusted testsers before delivering it to the mainstream.

But your suggestion to use `about:config` setting to toggle it is clearly the right solution.

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

SmallOrangFruit — Mon, 05 Oct 2026 20:23:35 GMT

I had updated my firefox and it made everything circular, i can tolerate minorly round corners but that was so extreme : /
tysm for this cause it at least let me go back to the more rectangular shaped boxes at least < 3
idk why they would change the ui that much and not give a config option when its that easy to change with that config???

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

Agentvirtuel — Thu, 08 Oct 2026 04:49:41 GMT

Bonjour

Just to see.
https://www.camp-firefox.de/forum/thema/141025-auf-die-schnelle-nova-to-proton-ein-umfassendes-css/?postID=1295648#post1295648

userChrome.css and userContent.css, together.

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

JohnDoe6 — Fri, 09 Oct 2026 11:05:56 GMT

I specifically registered to say thanks. Very underrated answer. The rounded tab names just came to my stable version and was driving me crazy, so ugly. Thanks! You'd be my guest for a beer if I knew you irl.

Re: Hate the rounded corners inside firefox. Disabled them in windows 11 a long time ago, now you have them inside firefox itself.

Zernando — Fri, 09 Oct 2026 13:25:51 GMT

I followed these steps with version 157.0.1 and they no longer work (os = linux mint). Did all 3: userStyle.css, userContent.css, toolkit.legacyUserProfileCustomizations.stylesheets = True.

What did work:

about:config / browser.nova.enabled = False

Ridiculous to keep changing the UI every few years and not put a simple toggle in the GUI. Do better mozilla.