Is a left-side tab close button in Firefox possible?

As luck would have it, the Firefox UI can be customized in ~/Library/Application Support/Firefox/Profiles/<PROFILE_ID>/chrome/userChrome.css. Add the following to that file (valid for Firefox v98):

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

.tabbrowser-tab .tab-throbber,
.tabbrowser-tab .tab-icon-image,
.tabbrowser-tab .tab-sharing-icon-overlay,
.tabbrowser-tab .tab-icon-overlay,
.tabbrowser-tab .tab-label-container,
.tabbrowser-tab .tab-icon-sound {
  -moz-box-ordinal-group: 2 !important;
}
.tabbrowser-tab .tab-label-container {
  margin-left: 2px;
}
.tabbrowser-tab .tab-icon-image {
  margin-left: 3px;
}
.tabbrowser-tab .tab-close-button {
  margin-left: -5px !important;
  margin-right: 2.5px !important;
}
.tabbrowser-tab:not([pinned="true"]):hover .tab-close-button {
  display: -moz-box !important;
}
.tabbrowser-tab:not([pinned="true"]):hover .tab-icon-stack,
.tabbrowser-tab:not([pinned="true"]):hover .tab-throbber,
.tab-close-button {
  display: none;
}

Also, userChrome.css is disabled by default in Firefox 69+, so go to about:config and set toolkit.legacyUserProfileCustomizations.stylesheets to true

Thanks to https://support.mozilla.org/en-US/questions/1157451 for inspiration. I've also added a Gist with this info.

Is a left-side tab close button in Firefox possible?

Related

Recent Posts