If you have accidentally removed bookmarks then use "Organize > Undo" in the bookmarks manager (Bookmarks > Show All Bookmarks) to get them back. The Organize button is the first of the three buttons next to the Back and Forward buttons on the toolbar in the Library (Bookmarks Manager). That only works if you haven't closed Firefox. If it didn't work then you can restore the bookmarks from a JSON backup in the bookmarkbackups folder.

• Bookmarks > Show All Bookmarks > Import & Backup > Restore

This will replace all current bookmarks and you lose bookmarks that were added since that backup was created. See:

• http://kb.mozillazine.org/Backing_up_and_restoring_bookmarks_-_Firefox

In that case you need to export the current bookmarks to an HTML file before doing the restore and import that HTML file after you have restored the JSON backup.

• Bookmark Deduplicator: https://addons.mozilla.org/firefox/addon/bookmark-deduplicator/

Thank you and this was quiet helpful. I was able to restore my bookmark

In the latest Nightly version i don't see an Undo option in any of the menus within the Bookmarks Manager (Library) but it still works using Edit -> Undo once the Manager window is open.

However, if you delete a link from the History then Undo doesn't work. Is this a bug?