You can save a copy of Firefox Bookmarks to a Windows computer or Mac. It is not possible to use the Firefox mobile app to export bookmarks.
Step 1. Open Firefox
The Firefox app icon looks like an orange fox wrapped around a blue globe.
Step 2. Click ☰
This icon is located at the top right of the Firefox window. It opens a drop-down menu.
Step 3. Select Library
The option Library is at the top of the drop-down menu.
Step 4. Click Bookmarks
This option is in the middle of the drop-down menu. It opens a new menu with all the Firefox bookmarks.
Step 5. Choose Show All Bookmarks
You will find this link in the lower left corner of the drop-down menu. Click on it to open a new window.
Step 6. Select Import and Backup
It's the star and arrow icon at the top of the bookmarks library. Click on it to open a drop-down menu.
If you're using a Mac, click the star icon at the top of the window
Step 7. Click Export Bookmarks as HTML
This option is at the bottom of the drop-down menu. It allows you to open a file explorer (on a computer running Windows) or the Finder (on a Mac).
Step 8. Enter a name for your bookmarks file
In the field File name Where name, type the name you want to give to your bookmarks (for example "2019 bookmarks").
Step 9. Select a save location
In the left side pane of the window, click on the folder (for example Office) where you want to save your bookmarks.
Step 10. Click Save
This is the button at the bottom right of the window. Click on it to save your bookmarks file in the selected folder with the name you chose.
Step 11. Close the Library window
At this point, you can start browsing Firefox again. Closing the window Library will not delete your bookmarks or delete the exported bookmarks file.