Firefox has got the support to import Logins and Passwords from Firefox, Bitwarden, and Chrome CSV files.
Recently, we’ve reported Firefox has gained the ability to export logins and passwords saved to its Password Manager, Lockwise to a CSV file.
Since then, Mozilla has been working on implementing passwords import support in Firefox and it has been landed in Nightly.
First things first, here is how you can backup your Firefox passwords to a CSV file.
!. Click on Firefox menu, select “Logins and Passwords”
2. Click on the three-dot (..) icon and select “Export Logins”
3. Firefox warns your passwords will be saved to a plain text file which anyone can open and read, click “Export”
4. Enter Windows password and click “OK”
5. Click “Save” for the passwords to be saved to logins.csv file.
To Import Logins and Passwords from a CSV file into Firefox
1. Launch Firefox browser
2. Click on the menu and select “Logins and passwords”
3. Click on the (…) icon and select “Import from a File”

3. Select the logins.CSV file which you’ve exported above or Chrome Passwords CSV file which you’ve created by selecting the “Export Passwords” button in the chrome://settigs/passwords page.
4. Done, the logins and passwords will be imported into Firefox Lockwise and you can see them on about:logins page.
Note: as of now, Firefox doesn’t show a confirmation message when the import is successful. The “import summary report” and confirmation dialog being prepared by Mozilla.
Related articles:
Firefox can now Export Logins and Passwords to a CSV file
Mozilla begins to disable Windows Password Prompt in about:logins on Firefox 76 & 77
Google redesigns Chrome Passwords Export and Import feature