Hmm, there might be an easier way, but here's one way: create a custom style rule to style those tabs. This is an example:

@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);
.tab-content[pinned="true"]:not([selected="true"]) { /* Space next to icon */
    padding-left: 3px !important;
    padding-right: 3px !important;
}
.tab-background[pinned="true"]:not([selected="true"]) {
    display: none !important;
}

The result is illustrated in the attached "before and after" screen shot. Is this along the lines you want?

You can apply custom style rules to Firefox's user interface either by using the Stylish extension or by creating/editing a userChrome.css file. Personally I tend to use Stylish because it is fast to tweak and preview changes when editing a rule.

JScher,

Thank you for the solution, and the detailed reply.

I tried this, using the Stylish extension.

It did indeed reduce the size of the pinned tabs, as intended.

However, these tabs were no longer functional--when you click on them, nothing happens.

I tried increasing the px to 5 but same result.

Any thoughts?

Thanks very much for your help.

How many pinned tabs do you have?

It is more common to reduce the minimum width of unpinned tabs to have more fit on the tab bar.

• Custom Tab Width: https://addons.mozilla.org/firefox/addon/custom-tab-width/

Hi ApersoninDC, sorry about that. I must not have tested again after adding the second rule, which suppresses the background. Allowing the background makes the tabs larger and they work. So finding a way to shrink the background without supressing it completely would be the logical next step. Until then, delete those last 3 lines.

thankyou jscher2000. just what i was looking for. i used the above, scrpt in the add-on minus the last 3 lines. the result works-- thankyou! thankyou! --- visually not brilliant to look at as the icon of the tab is hard left to edge (on left) and some space on the right. it would be nicer visually if the icon of the pinned tab was centred.

but I changed the left hand side padding to 7px. it centres. (nice preview function of the add-on). does not make sense to me, but it worked!