One of these may help you: https://www.ghacks.net/2018/07/18/how-to-export-firefox-passwords-in-firefox-57/ ++++++++++++++++++++++++++++++++++++ http://www.nirsoft.net/utils/passwordfox.html (Win) PasswordFox v1.58 - Extract the usernames/passwords stored in Firefox Copyright (c) 2008 - 2017 Nir Sofer

Note: Some anti-virus show false positive. ++++++++++++++++++++++++++++++++++ Easily export your passwords from Firefox. https://github.com/kspearrin/ff-password-exporter

Export your passwords from Firefox in a portable CSV or JSON format. It works on Windows, macOS, and Linux. +++++++++++++++++++++++++++++++++++ 3 Tools to Decrypt and Recover Passwords Saved in Firefox • Raymond CC https://www.raymond.cc/blog/how-to-find-hidden-passwords-in-firefox/ +++++++++++++++++++++++++++++++++++ https://www.ghacks.net/2018/07/18/how-to-export-firefox-passwords-in-firefox-57/ ++++++++++++++++++++++++++++++++++++ https://github.com/kspearrin/ff-password-exporter

Unfortunately none of the suggestions is for IMPORTING passwords to Firefox. All are for exporting passwords from Firefox.

Firefox doesn't handle the CSV format for logins / password data. The old Legacy version of Firefox (Fx56 Australis and earlier versions) did have some 3rd party add-ons available which would export and import via CSV, but the Quantum versions don't support the defunct Legacy format extensions.

It's probably possible to write a script that adds passwords from a CSV file, but if you don't find one online, it's going to take some work.

First, because legacy extensions no longer run, you will need to execute a "legacy" script in the Browser Console. To do that, you need to turn on "chrome debugging" as follows:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button promising to be careful or accepting the risk.

(2) In the search box above the list, type or paste devt and pause while the list is filtered

(3) Double-click the devtools.chrome.enabled preference to switch the value from false to true

And then you may need more information about the Browser Console: https://developer.mozilla.org/docs/Tools/Browser_Console

This is a script that adds a single saved login:

/*
Sequence of fields for init():
login.hostname, login.formSubmitURL, login.httpRealm,
login.username, login.password, login.usernameField, login.passwordField
*/
try {
  var loginInfo = Components.classes["@mozilla.org/login-manager/loginInfo;1"].createInstance(Components.interfaces.nsILoginInfo);
  // Create the new login info object
  loginInfo.init("https://www.jeffersonscher.com", "https://www.jeffersonscher.com/res/logintest.html", null,
    "me", "secret123", "uname", "pass");
  // Add the new login to Firefox's password manager
  Services.logins.addLogin(loginInfo);
} catch (err) {
  console.log('Problem adding login: '+err);
}

Then that should show up in the Saved Logins dialog, and it may or may not auto-populate on the test page https://www.jeffersonscher.com/res/logintest.html (I got flaky results).

So what's missing from this equation is the code to read your CSV file, extract out the fields for each login, and assemble them into the correct format to add to Firefox.