Recover saved Firefox and Thunderbird passwords from a profile folder (key4.db + logins.json). Runs entirely in your browser.
Firefox and Thunderbird store saved website logins in your profile folder, encrypted with the NSS security library. Two files hold everything needed to recover them: - **key4.db** - a SQLite database containing the global salt and the encrypted master key - **logins.json** - the encrypted usernames and passwords for each saved site This tool reproduces the same decryption that the well-known firefox_decrypt and firepwd utilities perform, but without installing Python. Upload your profile folder and it recovers the plaintext logins locally - nothing is uploaded to any server.
Input:
key4.db + logins.json (Firefox profile folder)
Output:
https://example.com | alice | hunter2
Are my files uploaded anywhere?
No. Decryption happens entirely in your browser using JavaScript. Your key4.db and logins.json never leave your device. (The SQLite reader's WebAssembly engine is fetched from a CDN, but your data is never sent anywhere.)
What if my profile has a master (primary) password?
Enter it in the Master Password field. Without it the encrypted master key cannot be unwrapped. If the field is left empty and the profile is protected, the tool will tell you a password is required.
Which files do I need?
key4.db and logins.json, both from the same Firefox profile folder. You can select the whole profile folder and the tool will pick them out automatically.
Does this work with old key3.db profiles?
No. Only key4.db (Firefox 58 and newer) is supported. key3.db uses a legacy Berkeley DB format that this tool does not read.
Does it work for Thunderbird?
Yes. Thunderbird uses the same NSS storage format, so its key4.db and logins.json decrypt the same way.