What is the OAuth consent screen?

The OAuth consent screen is the dialog Google shows when a user clicks "Continue with Google" for the first time. It tells the user which app is asking for access and what information it wants.

What it looks like

The screen shows your app's name, the email or profile information it's requesting, and buttons to allow or deny. This is Google's way of asking the user: "This app wants to know who you are. OK?"

Testing vs published

When you first set up OAuth in Google Cloud Console, your app starts in Testing mode. This means:

• Only up to 100 users you manually add can sign in
• The consent screen shows a warning ("This app hasn't been verified")
• Users can still click through the warning

To remove the warning and allow unlimited users, you'd need to publish your app and go through Google's verification process. For a development project, testing mode is fine.

What permissions look like

OAuth uses scopes to define what the app can access. The scopes you'll typically request are:

• userinfo.email — the user's email address
• userinfo.profile — the user's name and profile picture

These are read-only. The app can see who the user is but can't change anything in their Google account.