/home/<YourUsername>/.mozilla/firefox/<profile folder>/places.sqlite
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Once inside your profile folder, your bookmarks are stored in two key places: where are firefox bookmarks kept
~/Library/Application Support/Firefox/Profiles/[random-string].default-release/ ~/.mozilla/firefox/[random-string].default-release/
If you’re looking for your Firefox bookmarks, they aren’t in a simple .txt file. They are stored in a file. /home/<YourUsername>/
The active bookmarks data is stored inside the user's specific Firefox Profile folder. The path varies depending on the operating system.
Firefox bookmarks are kept in the places.sqlite file located within the hidden Profile folder. For users attempting to back up data or retrieve lost bookmarks, using the "Open Folder" link in the Troubleshooting Information menu is the most efficient way to locate the correct directory. The active bookmarks data is stored inside the
Library → Bookmarks → Import and Backup → Export Bookmarks to HTML