- Free tier: unlimited logins for 7,000 active users/month, authentication with email/password and up to 2 social providers
- Pros: lots of providers, great documentation, support passwordless authentication, UI provided, compatible with iOS Touch ID, offers welcome emails and tasks triggers
- Limitations: active users are users who logged in the last 30 days
- Free tier: 50,000 active users/month (active means at least one activity during a calendar month)
- Pros: supports mobile and web apps, multiple authentication providers (Facebook, Twitter, Google, ...)
- Limitations: Cognito Sync (users data synchornization) is only included in the AWS 1 year free tier in the limit of 10GB storage and 1,000,000 sync operations/month
- Free tier: always free, unlimited users
- Pros: offers multiple login providers for free (anonymous, email, Google, Facebook, Twitter, GitHub), provide welcome emails triggers, integrates well with Firebase database security rules, libraries for multiple platform, UI available for Android, iOS and web.
- Free tier: always free, unlimited users
- Pros: offers multiple login providers (email, custom with in-app browser, Google, Facebook, Twitter, GitHub, Instagram, LinkedIn), provide forms
- Free tier: unlimited users, 10k API calls/mo
- Pros: complete user authentication, authorization and management through their API, client libraries for multiple languages