The authentication app for Facebook is usually a third-party authenticator app that generates 6-digit login codes, such as Google Authenticator, Microsoft Authenticator, Duo Mobile, or Authy. Facebook lets you choose an authentication app under its two-factor authentication settings rather than requiring one specific app.

How it works

When you turn on two-factor authentication in Facebook, you can select Use authentication app and scan a QR code or enter a setup code. After that, the app generates time-based verification codes you enter when Facebook asks for them.

Quick answer

If you’re asking “which app should I download?”, the safest answer is: any reputable authenticator app that supports TOTP codes. Facebook supports this setup, and many users also use passkeys on supported devices as a newer sign-in option.

What to do next

  • Open Facebook settings.
  • Go to Accounts Center.
  • Tap Password and security.
  • Choose Two-factor authentication.
  • Select Authentication app and follow the QR-code setup.

If you want, I can also tell you the best authenticator app for iPhone or Android.