Firefox Close Button On Every Tab Minimum Width Glitch

I have installed and uninstalled so many plug-ins for Firefox that I long ago lost count.  As of this writing I have around 35 installed and maybe 20 or so enabled.  So, when I get a little glitch here or there in the Firefox interface, I usually figure it’s probably my fault and that one of my add-ons is causing it either intentionally (for the add-on, not for me) or because I configured, or didn’t configure, something that messed up whatever it was that I noticed.

However, I don’t just let it go without doing some troubleshooting.

Today, I stumbled across the solution to one of my major annoyances.  I routinely go into Firefox’s about:config to ensure that my browser.tabs.closeButtons is set to 1 which means that there should be a X one each and every tab in Firefox so that you can close any tab you want with a single click.  In other words, there is no need to select the tab in order to close it.

The catch is that even though that parameter was indeed set, and reset, to 1 every time, my close buttons seemed to disappear after I had been using Firefox for a while.

browser.tabs.tabMinWidth

I’ve done a fair amount of reading about Firefox.  Unfortunately, not everything out there is very good or very accurate.  In particular, the numerous articles about how to make Firefox faster by adjusting about:config parameters are misleading at best, and untrue at worst. 

Along the way, I read about setting your mimimum tab width in Firefox.  The point is that by making it smaller, more tabs will fit across a single row.  Google has made Title tags worthless by making every savvy webmaster fill them with keywords instead of a useful title. That means it really doesn’t matter how small your tabs are since most of the time, whatever text is displayed in the tab won’t be unique enough to distinguish one tab from another. So, like many others before me, I cranked the minimum tab width parameter down to 70 or 75 depending upon my mood.

It turns out, that on a tab that is too small, Firefox does not put an X to close the tab regardless of what the about:config browser.tabs.tabMinWidth setting is.  With a small setting, the browser determines that you want a smaller tab and that there is no longer any room for a close button.

In my Firefox installation, testing has revealed that a minimum tab width setting of 138 is required to always have a close button displayed no matter how many tabs you have open.  That number may be substantially different for your installation because I do have some plug-ins that do things to my tabs like color them and allow me to close all tabs to the right, and so on.

If you want a close button on all of your tabs and you already have set your browser.tabs.closeButtons to 1, check your browser.tabs.tabMinWidth setting.  Try bumping it up to 140 or so and see if all of your tabs have close buttons now.  Then, experiment with smaller numbers until you get the smallest tab size that will work.  Then, it’s up to you to decide which you want more, smaller tabs, or easily accessible close buttons.

For me, I want that X on every tab all the time because sometimes I end up with dozens of tabs open while searching for some information, and once I find it, I just want to close all the other tabs about that topic fast and easy.  That is, unless they are all grouped at the right end, in which case I can just Close All Tabs to Right.