How do I turn on two-step login?

Two-step login is optional. Once it's on, after your email code or password you also enter a code from an authenticator app such as Google Authenticator, 1Password or Authy.

When you turn it on we show recovery codes once. Save them somewhere safe: each works once if you lose your phone. To turn two-step off later, you need to have signed in with your authenticator code.