Sign in using App Passwords
An App password is a 16-digit passcode that gives an app or device permission to access your Google Account, you only have to enter an App password once per app or device, so don’t worry about memorizing it, even when you use 2-Step-Verification.
Note: If you have iOS 8.3 on your iPhone or OSX 10.10.3 on your Mac, you will no longer have to use App passwords to use 2-Step Verification.
Why you may need an App password
When you sign up for 2-Step Verification, we normally send you verification codes. However, these codes do not work with some apps and devices, like Gmail on your iPhone or iPad, Thunderbird, and Outlook. Instead, you'll need to authorize the app or device for the first-time Google sign-in by generating and entering an App password. With App password, you only need to enter it once.
How to generate an App password
- Visit your App passwords page. You may be asked to sign in to your Google Account.
- At the bottom, click Select app and choose the app you’re using.
- Click Select device and choose the device you’re using.
- Select Generate.
- Follow the instructions to enter the App password (the 16 character code in the yellow bar) on your device.
- Select Done.
Once you are finished, you won’t see that App password code again. However, you will see a list of apps and devices you've created App passwords for.
Note: For less secure apps, you cannot create an App password.
Forgot your App password
Every App password is only used once. Don't worry, you can always generate a new App password whenever you need one, even for a device or application you've authorized before. So if you forgot your App password, create a new one.
Can't sign in to my Gmail app
See full help page there Can’t sign in to my email app.