Export Firefox bookmarks to an HTML file to back up or transfer bookmarks
5. In the Export Bookmarks File window that opens, choose a location to save the file, which is named bookmarks by default. Click the Save button.
Export usernames and passwords
1. Click the menu button2. Click Passwords. The Firefox password page will open in a new tab.
3. Click the menu icon (three dots), then click Export Passwords…
4. A dialog box will appear to remind you that passwords are saved as readable text. Click Continue with export to continue.
5. Choose the file name and location where this exported data will be saved and click Save.