Go to the [https://addons.mozilla.org/en-US/firefox/ Mozilla Add-ons Web Page] {web Link} (There’s a lot of good stuff here) and search for what you want.

Thank you bunches I will check it out.

This one seems to do exactly what you want: https://addons.mozilla.org/en-US/firefox/addon/bookmark-deduplicator/?src=search

If you use Sync then best is to disconnect Sync while performing maintenance/repair efforts to files in the Firefox profile folder. Best is to reconnect one device at the time and wait for the initial Sync to finish before connecting another device once you have fixed the bookmarks. ---- You can check for problems with the <b>places.sqlite</b> database (bookmarks and history) in the Firefox profile folder. *https://addons.mozilla.org/firefox/addon/places-maintenance/ See also: *http://kb.mozillazine.org/Locked_or_damaged_places.sqlite *https://support.mozilla.org/en-US/kb/Bookmarks+not+saved#w_fix-the-bookmarks-file