Bookmark Backup od Mona

Auto Bookmark Backup is a lightweight and reliable Firefox extension that automatically backs up your bookmarks every day or week. The extension exports your entire bookmark tree into a clean .json file and saves it to your computer. No manual action is required — just install it, and your bookmarks will be safely backed up on a regular schedule.
Whether you're a developer, researcher, or everyday browser user, this add-on helps ensure your valuable bookmarks are never lost.