How to Turn On Two-Step Verification for Gmail

A password on its own is one leak away from being someone else's. Two-step verification is not a Gmail setting, it belongs to the Google Account underneath it, which is why it cannot be found anywhere in the mail settings.

Open the security page

In Gmail on the web, click your profile picture at the top right, then Manage your Google Account. Choose Security in the left menu and scroll to How you sign in to Google.

Start the setup

Click 2-Step Verification, then Get started. Google asks for your password again before letting you change anything. Have the phone you use most within reach.

Choose a second step

Google proposes Google prompts, a tap-to-approve notification on a phone already signed in to the account, which is the default and needs no extra app. An Authenticator app generates six-digit codes and works with no signal at all. A security key is the strongest option and the most fiddly. Pick one, follow the on-screen check, then click Turn on.

Add a phone number as backup

Add a number for text or voice codes as a fallback. Codes by text are the weakest step of the set, so treat that as the spare rather than the main method.

Save your backup codes

Back on the Security page, open Backup codes and choose Download or Print. There are ten, each usable once. Keep them somewhere that is not the phone holding the other step, since a printout in a drawer survives a lost handset and a note in the phone does not.

Old apps stop connecting. Anything that signed in with the password alone, such as a desktop mail client or an office printer, fails afterward. Generate an App password from the same Security page and use that string in place of the password in that one app.

Losing both is expensive. Without the phone and without the codes, the only way back in is Google account recovery, which asks about past passwords and account history and can take several days to decide. Save the codes before you need them.

Sources. Turn on 2-Step Verification - Computer - Google Account Help, Sign in with backup codes - Computer - Google Account Help, Sign in with app passwords - Google Account Help.