Firefox IconBar

A Firefox extension for icon bookmarks, similar to Edge's sidebar. Will look for bookmarks in the folder: Other Bookmarks > IconsBar

https://addons.mozilla.org/en-US/firefox/addon/iconbar/

NOTE: In order to have the thin sidebar, you need to create/edit your userChrome.css file.

How to create/edit userChrome.css

1. Open Firefox, and in your url bar type about:profiles

2. Look for the Profile that says "This is the profile in use and it cannot be deleted." and click the Open Folder of the Root Directory section

3. Open the chrome folder (create it if it doesn't exists)

4. Open userChrome.css inside the chrome folder (create it if it doesn't exists)

5. Add the following code:

/* remove maximum/minimum width restriction of IconBar */
#sidebar-box:is([sidebarcommand="_9dba9848-1289-4662-ac96-487a72c7e9fe_-sidebar-action"]) {
  max-width: 60px !important;
  min-width: 60px !important;
  width: 60px !important;
}

/* Minimize IconBar header */
#sidebar-box:is([sidebarcommand="_9dba9848-1289-4662-ac96-487a72c7e9fe_-sidebar-action"]) #sidebar-header {
  height: 0 !important;
  padding: 0 !important;
  margin: 0 !important;
  opacity: 0 !important;
}

/* Hide IconBar header */
#sidebar-box:is([sidebarcommand="_9dba9848-1289-4662-ac96-487a72c7e9fe_-sidebar-action"]) #sidebar-header #sidebar-switcher-target {
  opacity: 0 !important;
}

6. Set Firefox to look for userChrome.css at startup: In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk. In the search box above the list, type or paste userprof and pause while the list is filtered. Double-click the toolkit.legacyUserProfileCustomizations.stylesheets preference to switch the value from false to true.

7. Restart Firefox