Agree 1000% – the lack of tab separators is almost enough to drive me to Edge, and I don’t even have any visual problems.
Mozilla, please, we’re begging you. Was anyone complaining about the existence of tab separators? I’m going to take a guess the answer is a solid no.
Same problem here, tabs with no favicon now just look as blank space between others, and are very difficult to locate (I am reducing tabs size to minimum to get as many as possible visible).
Not against changes, but here I need an option to bring the borders back as this is making my life as user more difficult.
For now, I have set up “browser.proton.enabled” to false in about:config as suggested above - not sure what I lose with that, but I surely gain useability and visibility for now 
I downloaded Brave because of this. First time in 10 years I’ve considered dropping Firefox. I presume “browser.proton.enabled” will deprecate.
As Martin Brinkmann points out, Firefox has continued to bleed market share as Mozilla has shown a pattern of making decisions that alienate its userbase.
I don’t mean to sound unkind or attacking. Hope this issue gets looked at.
Just chiming in to say that this tab bar usability regression is so awful that for the first time in 20 years I’m looking to switch to another browser. I always have plenty of tabs open, but without separators and proper contrast between the tab-bar and main browser area it’s become virtually impossible to use.
Yep, same here. This update looks dreadful, and I’ve spent hours trying to get the old look back. It took me forever just to find this discussion, after realizing that the main thing that was driving me nuts was the lack of lines around the tabs. The proton thingy does look a little better, but I’d prefer to have the theme look like it did, pre-update.
I do not like the new tab visuals either. Tab separator or not, there is a large amount of space wasted for empty regions between tabs + the fadeout effect.
I would very much like an option to enable hard tab separators, square tabs, and as much utilization of space as possible. Firefox has traditionally been very good wtih lots of tabs (its scrolling tab block is excellent, Chrome was unusable with hundreds of tabs). Now it’s much worse for that — the title previews are extremely short.
If not going back to separators OR removing large margins and fadeout effect, the tabs could be at least made to have wider minimum length. As it is, the tab title is less than 6 characters long!
A guess: maybe the new design will, eventually, lend itself to tab groups – a long-lost feature.
Please, no knee-jerk comments about Google or Chrome.
Thank you! It looked a complete mess! Found this post by searching how to reverse it. So sick of having visual changes forced on me for everything.
The new update…
Disabled it via “browser.proton.enabled”. This is not the first time firefox has alienated me. Trading so-called design ideas over real usability is what has killed Windows 8 on the desktop, and others. Firefox is already on a declining userbase since long, had to lay off staff and projects. So why chase away even more of your users? I just don’t understand.
I’m not IT-savvy and don’t have great eyesight. I cannot see where 1 open tab ends and another begins with the new colours. I find the thin line boxes all over pages intrusive; they also make reading more difficult for me. Please make it possible to have something simpler.
Exactly. I agree with most opinions here. This change is just terrible and completely needless. They almost destroyed firefox for android, and now this.
I’ll try to use the solution proposed in this thread.
same here! I can’t develop new themes, I can’t write code to toggle things on and off. So please think about not IT Savvy users… I really would like the common-sense possibility to distinguish my tabs from each other back. And also would like to second the already many times expressed thought that it is super sad that these type of changes are simply imposed, removing features that were actually ultra useful… Have been loyal to Firefox for years and wish to remain! Please don`t fix things that are not broken!!
Thanks for the tip @Jamdar ! I did disable “browser.proton” and it really makes a difference: at least I can see where a tab ends and another starts !
As a complement to Firefox, you might like an extension that enables vertical tabs. I use Tree Style Tab, use of which can become complex; not for you.
Simpler extensions include Visual Tabs. Two screenshots:
The second shot shows the visual feature of the extension; you can preview a tab before clicking on it.
Just to add my voice.
This is a terrible change for me. I always have loads of tabs open and this change forces a lot of concentration just to find the different tabs.
My first action after seeing the new design was looking for themes that improve the readability of the UI and the only working solution I found was disabling “browser.proton.enabled”.
Addition: The new tabs also eat more vertical space. Why?
Guys, anyone tried to fix it with CSS? Is this solution not working anymore?
Hmm, it seems it works! Here are my 2 custom styling files (enable toolkit.legacyUserProfileCustomizations.stylesheets option in about:config and extract the chrome folder from the archive into your profile folder): http://popov654.pp.ru/chrome.css
@Alex654 , link is not working anymore it seems:
The requested URL /chrome.css was not found on this server
To all here, see https://www.userchrome.org/firefox-89-styling-proton-ui.html#tabstyler from @jscher2000 which does the trick.
Thanks to him for the work.
