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. Check these out; '''[https://addons.mozilla.org/en-US/firefox/addon/bookmarks-checker/?src=collection&collection_id=33bf10fa-666d-45a2-9bc9-491ce21671c6 Bookmarks Checker - check for bad links]''' {web link} Check favorites for broken or bad links. It checks for bad links and displays a report if it finds something. Check for 404 links, timeout links. '''[https://addons.mozilla.org/en-US/firefox/addon/bookmark-duplicate-cleaner/?src=external-Add-ons_Manager_Context_Menu-extension Bookmark Duplicate Cleaner]''' {web link} Scans for bookmark duplicates and allows you to delete them