自建网站认证方案咨询：Google Sign-In API是否免费及与Cloud Identity的差异

Hey there! Let’s break down your two key questions about Google’s authentication tools clearly— I’ve helped a bunch of devs navigate these for their self-hosted sites, so I’ll keep it straightforward.

Is Google Sign-In API free to use? #

Absolutely—the core Google Sign-In API is free for most self-hosted website use cases. It’s part of Google’s Identity Platform, and the free tier covers all the basics you’ll need:

• Letting users log into your site with their existing Google accounts (no need for them to create a brand new account on your platform)
• Accessing basic user profile data like name, email address, and profile photo
• Secure OAuth 2.0/OpenID Connect flows for safe authentication

There’s a free monthly request limit (currently 100,000 sign-in requests per month), which is way more than enough for most small to medium-sized self-hosted sites. If you ever exceed that limit, you’ll need to enable billing and pay for additional requests, but for most folks starting out, the free tier is totally sufficient. You don’t even need a paid Google Cloud account to get started with the free features.

What are the key differences between Google Sign-In API and Cloud Identity? #

These two tools serve completely different purposes, so here’s a breakdown of their core distinctions:

• Core Purpose
  • Google Sign-In: Built for consumer-facing authentication. It’s all about making it easy for end users (regular people with personal Google accounts) to log into third-party websites/apps without creating new credentials.
  • Cloud Identity: Built for enterprise identity management. It’s designed for businesses to manage employee accounts, control access to company resources (like Google Workspace apps, internal tools), and enforce security policies across their organization.
• Target Users
  • Google Sign-In: Your website’s visitors (individuals with personal Google accounts).
  • Cloud Identity: IT administrators and businesses managing employee access to corporate systems.
• Key Features
  • Google Sign-In: Focuses on login experience—one-tap sign-ins, secure token-based auth, profile data retrieval, and integration with common front-end frameworks.
  • Cloud Identity: Focuses on identity governance—employee account lifecycle management (onboarding/offboarding), single sign-on (SSO) for enterprise apps, mandatory multi-factor authentication (MFA), device management, and granular permission controls.
• Pricing Model
  • Google Sign-In: Free tier for most use cases, pay-as-you-go for high-volume requests.
  • Cloud Identity: Subscription-based pricing per user, with tiered plans (basic, premium) that add advanced security and management features.

内容的提问来源于stack exchange，提问作者John