It’s not uncommon to see people ending up with duplicate URLs in their browser Bookmarks/Favorites over a period of time. Finding duplicates by comparing the target URL may be a tedious task especially if you have a lengthy favorites list. Here are two useful tools that can help you easily find and remove duplicate URLs from Internet Explorer Favorites and Mozilla Firefox Bookmarks.
FavoritesView displays the list of all your Favorties (of Internet Explorer browser) and bookmarks (of Netscape/Mozilla browsers) in a single page. Each line in the list specifies the title of the item, the URL address, the created/modified date of the bookmark item, and the folder name. FavoritesView also allows you to locate duplicate URL addresses in your Favorites/Bookmarks or find specific item by specifying the URL or the title.
AM-DeadLink is popular tool which can detect dead links in Internet Explorer Favorites, Firefox and Opera Bookmarks. If a bookmark has become unavailable you can verify and delete it permanently. AM-DeadLink can also find duplicates in browser favorites/bookmarks.