Overview

Sign in with Google helps you to quickly manage user authentication on your website. Users sign into a Google Account, provide their consent, and securely share their profile information with your platform.

Customizable buttons and multiple flows are supported for user sign-up and sign-in.

Sign-up refers to the steps to obtain a Google Account holder's consent to share their profile information with your platform. Typically, a new account is created on your site using this shared data, but this is not a requirement.

Sign-in refers to logging users into your website using their active Google Account with a personalized sign-in button or One Tap and Automatic sign-in for users already logged in to their Google Account.

See the Case Studies for some success stories of Sign In With Google integrations.

You can also use the Google Identity Services authorization API, which lets you obtain an access token for use with Google APIs, or to access user data.

User privacy

Data from Sign in with Google is not used for ads or other non-security purposes.

Use cases

Some of the reasons to add Sign in with Google to your site are:

• Add a visibly trusted and secure Sign in with Google button to an account creation or settings page.
• Pre-populate new accounts with consensually shared data from a Google Account profile.
• Users can sign in once to a Google Account without re-entering usernames or passwords on other sites.
• On return visits, users can sign in automatically or with one click across an entire site.
• Use verified Google Accounts to protect comments, voting or forms from abuse, while allowing anonymity.

Supported features

These features are supported by Sign in with Google:

• Sign up, to optionally create a new account auto-filled from a Google Account profile.
• Sign in, using an account chooser to select from multiple accounts.
• Sign in with one tap, if you've already signed in to your Google Account.
• Sign in automatically, on return visits using your computer, phone or even multiple browser tabs.
• Sign out, to disable automatic sign-in across all your devices.

Note how account states may affect Sign in with Google:

• Suspending your Google Account stops sign in to all sites using Sign in with Google.
• Deleting your Google or partner account affects one, but not the other.

Compare to OAuth and OpenId Connect

OAuth and OpenId Connect are open standards that offer a wide range of configurable options to fine-tune the behavior of authentication and authorization flows. Refer to Google's OAuth documentation for more details.

Sign in with Google offers a single SDK to encompass several related offerings including a personalized button, One Tap, Automatic sign-in, and authorization. It aims to offer an easier and more secure experience for developers than the standard OAuth and OpenID Connect protocols, while providing a more seamless user experience.

• Sign in with Google is based on OAuth 2.0. The permissions that users granted through Sign in with Google are the same as those that they grant for OAuth, and the other way around.
• OAuth 2.0 is also the industry-standard protocol for authorization. It provides for a set of endpoints with which relying parties integrate using HTTP.
• Google Identity Services (GIS) APIs are available in several languages including JavaScript and HTML, that provide for both authentication and authorization.
• GIS separates the authentication moment from the authorization moment. In the authentication moment, a quick integration can be achieved by just integrating some UI elements into your website, such as the personalized button, One Tap, and automatic sign-in. These UI elements provide a consistent authentication UX across all third party websites. In the authorization moment, GIS triggers OAuth flows to return tokens for data access on behalf of the user.
• GIS authentication makes integration with relying parties easier, and reduces most of the OAuth and security knowledge burden on developers. You don't need to choose from various approaches to obtain access tokens or authorization code, or risk the consequences of choosing the wrong approach. While the OAuth 2.0 protocol exposes many details such as the request and response parameters of the HTTP endpoints, GIS handles these implementation details for you. Also, GIS includes some security implementations for Cross-Site Request Forgery (CSRF) protection by default.
• With the HTML API and Code Generator, the GIS authentication lowers the bar for relying parties integration even further. You don't need a JavaScript developer to generate the code. This reduces the level of OAuth experience required as well as time to implement.
• The GIS authorization UX is fully based on OAuth UX. However, the GIS JavaScript library adds some restrictions for easier and safer relying party integration.
• GIS also provides some features beyond the OAuth protocol. For example, it integrates Password Credential Manager API and Federated Credential Manager API.

With Google Identity Services, developers can use a dedicated and integrated service to help their users to sign in to the developer's website and apps with whatever login credentials the user chooses. The mission of GIS is to support and streamline the UX for multiple types of credentials, to lower the technical bar for the relying party integration.

Federated Credential Manager (FedCM)

As part of the Privacy Sandbox initiative, Chrome is phasing out support for third-party cookies. GIS integrates the FedCM API, which is a new privacy-preserving alternative to third-party cookies for federated identity providers. GIS begins a migration of all websites to FedCM on the Chrome browser in April 2024.

Key Point: For new web apps, you should always enable FedCM when integrating GIS to your website. For existing apps, you should migrate to FedCM to determine if your existing integration with GIS needs to be updated.

Separated authentication and authorization moments

To obtain an access token for use with Google APIs, or to access user data, you need to call the Google Identity Services authorization API. It's a separate JavaScript API, but packaged together with the authentication API.

If your website needs to call both authentication and authorization APIs, you need to call them separately at different moments. At the authentication moment, your website can integrate with One Tap, automatic sign-in and the Sign In with Google button to allow users to sign in or sign up to your website. At a later time, when accessing data from Google is required, you call the authorization API to ask for the consent and get access tokens for data access. This separation complies with our recommended incremental authorization best practice, in which the permissions are requested in context.

To enforce this separation, the authentication API can only return ID tokens which are used to sign in to your website, whereas the authorization API can only return code or access tokens which are used only for data access but not sign-in.

Thanks to this separation, users have consistent authentication experiences across different websites, which may increase user trust and usage, and result in better user conversion rates on your website. Also, due to this separation, Google Identity Services reduces the level of OAuth experience required and time to implement for authentication developers.

Key Point: Google Identity Services designates Sign in with Google for the authentication moment API and features. Google Identity Services designates the Authorization API for the authorization moment API and features.