Sign In with Persona What's this? MDN has switched to Persona, a safe and simple way to sign in with just your e-mail address. Learn more about why Mozilla is using Persona. Returning members: sign in with Persona and you'll be connected to your MDN profile (all your information is still here). New members: sign in with Persona first, then you'll be able to set up your new MDN profile. Sign in with Persona Username Password Confirm password Email address (optional)