Firefox 4 no longer uses that setting. It can be changed by using CSS. The bug report that introduced the change - Bug 574654 – Remove browser.tabs.tabMinWidth and browser.tabs.tabMaxWidth in favor of CSS

Thank you for the pointer. Now I have a more direct channel to raise my concern in.

Note that bug reports are not like forums and should not be used for discussions on issues.

Yes, well, I am not doing it to annoy. I like Firefox and this is why I take time to voice my concerns. This issue really annoys people and I hope it will be resolved properly, i.e. reinstate the minTabWidth config option.

Custom Tab Width: https://addons.mozilla.org/firefox/addon/221515/

You can easily go to the profile folder via Help > Troubleshooting Information

CSS code makes it also easier for theme makers to set a minimum tab width.

If you want to customize Firefox then you would still need to use user.js to initialize prefs and/or userChrome.css (user interface) and userContent.css (websites)
I use specific CSS files for each Firefox version and add an @import url("file.css"); rule to import the files that I want to use in a specific profile and keep userChrome.css clean and only use it for testing. All @import lines need to be before the @namespace line and each import file needs its own default @namespace line
It is very easy once you are used to it.

See http://kb.mozillazine.org/Editing_configuration#How_to_edit_configuration_files

I don't have the Help > Troubleshooting Information menu entry in 4.0b6 and as such have to make a slow manual search for something that may be related to Firefox (and may be hidden making me miss it completely).

Both minWidth and CSS could be enabled in FF if wanted. Several ways to implemement this but the simples would be to use minWidth is set or CSS is not. This way the user can always override the CSS (that may be buggy and unreadable by non-techies.).

I only configure Firefox through addons (none available for FF4.0b6 that can change the tab width) or through about:config. I can never remember the syntax nor the keywords for userChrome.css (nor even remember that name nor where the file is located). You may call about:config->TabMinWidth a convenience feature, but for some (like me) this is what make it doable. Not having it is a showstopper (for me and many others).

I appreciate your help to work around this issue, but the fundamental problem is that I really want the tabMinWidth option back into about:config. Maybe an addon could read the about:config settings and apply the tabMinWidth to userChrome.css automatically. I don't want to learn to make configuration files just for this one feature.

Does changing userChrome.css make Firefox read the new file automatically or do I have to restart Firefox? If I have to restart FF, then FF has lost a feature that I use (I change dynamically at work depending on the number of tabs open).

I really hope this issue is fixed properly as one of my alternatives is to begin using Chrome more (not even installed now, but it has automatically shrinking tabs (down to icon size), exactly what I want from FF).

It's absolutely ridiculous that a feature like this was removed in the first place. This better be brought back.

Like Firefox 4 couldn't be disappointing enough.

It is not removed. Only the steps to set the minimum tab width have changed and that can happen with other features as well. You have to get used to it that not everything is frozen and that such changes can happen at anytime.

Yeah, it is not removed, but now we have to install an addon to make dynamic changes to the tab width. To make static changes, we have to read a log of text, find files we don't know the names of, put unknown stuff in new files, just to change the tab width. Firefox user-friendliness is going down. :-( Other browser even include more sane defaults than Firefox, making tab changing less important.

But the developers can of course do as they see fit. I am just sad to see Firefox take such a turn for the worse.

Galmok,

If you don't have the knowledge or skills to tweak hidden preferences, why are you even using a beta pre-release version?

I honestly wish Mozilla would limit access to pre-release builds and allow only qualified addon developers and "testers" access to that part of the server. A password should be required to gain access to betas and a "no-whine" pledge should be required to get that password.

I do have the skills, but I find the change stupid at best. It is an often used feature to help improve the usability of Firefox. Making it this difficult to use is just not sane.

And I use the beta release to provide feed for just such a reason in hope the developers change their mind before the final release. I thought that was obvious.

This solution doesn't work anymore for some reason and I've yet to find a solution. I've both tried the add-on and editing userchrome.css . No dice.

I just now used the troubleshooting thingy to get a shortcut to userchrome.css and I'm severely annoyed at being transported into a tab instead of having a nice old modal (or whatever it's called) window pop up. Good job separating program functions from web functions that won't confuse novice users at all when malware authors get to work. Anyway this is the only entry I have in my userChrome.css: .tabbrowser-tab:not([pinned]) { max-width: 250px !important; min-width: 10px !important; }

Does not work.

Sorry for the OT but at least i managed to not sprinkle invective all over this post.

Are you using the Default theme (Tools > Add-ons > Themes) ?

Start Firefox in Diagnose Firefox issues using Troubleshoot Mode to check if one of the add-ons is causing the problem (switch to the DEFAULT theme: Tools > Add-ons > Themes).

• Don't make any changes on the Safe mode start window.

One again Mozilla finds new and innovative ways to break the UI.

There is a reason other companies with millions of users don't randomly remove settings and mess with UI elements for no apparent reason other than to make things a bit more tidy behind the scenes.

Here is an idea: Add a feature to Firefox that can check for altered settings to get an idea of how many users are using a particular customisation. If it is more than say 100 mandate the creation of either an alternative that does the same thing or the create of an add-on that does the same thing.

This is still not working for the official release. To a user the issue is simple, whats working before should continue to work!

Adding the following to userChrome.css worked for me:

.tabbrowser-tab[fadein]:not([pinned]) {

 min-width: 0px !important;
 max-width: 950px !important;

}

I'm curious; is using userChrome.css to do this, rather than one of the Add-ons which have been created, more efficient? (By which I mean, I've heard that Add-ons can impact browser performance.)

I just lost 30 minutes trying to shrink the width of the tabs, with no success. There is no userChrome.css file in neither the Firefex nor Users directory trees.

This should really be made as easy as possible, it's a important usability setting with ridiculous default value.

Unreal. I have the same issue. The CSS hack works, but the tabs float and dont slide left.

Firefox 4 has been the worst upgrade experience ever. They trampled on user settings and its disgusting to watch. They are becoming more and more featureless. And when they do that, they are poorly done version of Chrome.

I am disgusted by the tyranny shown by the foundation to remove stuff that has no reason . its like having no classic start menu in windows 7 or forcing ribbon into office. There are some people who will never like this crap new way of burning screen real estate. disgusting. Im so angry.

.tabbrowser-tab[fadein]:not([pinned]) {

min-width: 0px !important;
max-width: 950px !important;

}

this didnt work for me. The tabs no longer slid to the left when I used these settings.

My preferred setting would be to make min and max 160 and lock them there. instead i get tabs that dont slide . I like to close tabs with the (X) in the same place, but morons who destroy firefox like to move stuff around thats worked for YEARS for no good reason.

You have to learn something basic. Like say, the code from an 8086 (1978) still run on a Sandy Bridge (33 years and counting). You software-kiddies change things all the time and deprecate perfectly useful functions because you can. Its so bloody annoying and wrong and its funny, as hardware streaks into the future, with compilers today barely able to generate code that uses most of the CPU features and with software-kiddies blowing away gigs of memory with C++ and Java and not knowing any assembly, we sit here in a prison of mediocrity made by people who change and break things because they can. They literally hold generations of users hostage to change they way they, the autocrats, want.

Look at "8088 Corruption" An exercise in displaying full-motion video on the first IBM PC. Using assembly and video sound and coprocessors show how horrible programmers are these days. They are ignorant, abuse and waste memory and cpu constantly and then most are horrific at UI design. They have a powerful tool , modern development environments and they make terrible changes, abusive changes, and they waste CPU and memory.