If you aren't able to find an add-on for this, someone might be able to help with custom style rules. Applying those is a little more complicated, but do-able.

The only addons or guides I can find are for multi-row toolbars or to just increase font size.

This style rule will enlarge the text by 40% and the icons by 25%:

@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);
#PersonalToolbar .bookmark-item {
  font-size:140% !important;
}
.bookmark-item:not(#bookmarks-menu-button) > .toolbarbutton-icon {
  width: 20px !important; /* 25% over 16px default */
  height: 20px !important; /* 25% over 16px default */
}

I created a blank rule using the Stylish extension then pasted the above in. Screen shot attached showing before and after.

You can experiment with code like this in the userChrome.css file or with the Stylish extension if you prefer.

Add code to the userChrome.css file below the default @namespace line.

• http://kb.mozillazine.org/userChrome.css

@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"); /* only needed once */

#personal-bookmarks .bookmark-item > .toolbarbutton-text { font-size:12pt !important; font-weight:bold; }
#personal-bookmarks .bookmark-item > .toolbarbutton-icon { height:24px !important; width:24px !important; }

The customization files userChrome.css (user interface) and userContent.css (websites) are located in the chrome folder in the Firefox profile folder.

• http://kb.mozillazine.org/Editing_configuration

• [/questions/965032] Hoe kan ik de grootte van het letters van de bladwijzerbalk veranderen
• [/questions/905731] how do i increase the size of icons in the toolbars

Thanks. The only problem left is the font of bookmarks inside a folder is strangely larger than the font of the bookmarks (and folders) on the toolbar.

Also what is the namespace url for?

@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);

1. PersonalToolbar .bookmark-item {

 font-size:120% !important;

} .bookmark-item:not(#bookmarks-menu-button) > .toolbarbutton-icon {

 width: 22px !important;
 height: 22px !important;
 }

The code from JScher2000 also affects the code for the folders as well as it uses #PersonalToolbar .bookmark-item

The code that I posted should only work for the Bookmarks Toolbar and not within folders as it uses ".bookmark-item > .toolbarbutton-text" in the selector.

I see. Works perfectly, thanks guys.

Hi Joshopolis, I didn't notice that, but it's due to using a % measurement. As you drill down deeper and deeper into the hierarchy, it seems to multiply. Using a fixed measurement will make the text size in the folders the same as the bar.

@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);
#PersonalToolbar .bookmark-item {
  font-size:18px !important;
}
.bookmark-item:not(#bookmarks-menu-button) > .toolbarbutton-icon {
  width: 20px !important; /* 25% over 16px default */
  height: 20px !important; /* 25% over 16px default */
}