Best Authentication & Authorization APIs in 2026
The top 7 of 7 free Authentication & Authorization APIs, ranked by how easy they are to start with (API key, HTTPS, CORS), how reliable they are in our daily health checks, and what developers rate them. Auth0 API takes the top spot.
Last tested Oct 24, 2026 · Rankings update daily
Ranking
- 1
Auth0 API
Online · 583 msEasy to implement, adaptable authentication and authorization platform.
- Callable from the browser (CORS)
- HTTPS
apiKeyHTTPSCORS - 2
MojoAuth API
Online · 643 msSecure and modern passwordless authentication platform.
- Callable from the browser (CORS)
- HTTPS
apiKeyHTTPSCORS - 3
Warrant API
Online · 926 msAPIs for authorization and access control.
- Callable from the browser (CORS)
- HTTPS
apiKeyHTTPSCORS - 4
GetOTP API
Online · 674 msWith just a simple API call, you can implement your one time password verification flow without worrying about retry or multiple verification channel logic.
- HTTPS
apiKeyHTTPSNo CORS - 5
- 6
SAWO Labs API
Last check failedSimplify login and improve user experience by integrating passwordless authentication in your app.
- Callable from the browser (CORS)
- HTTPS
apiKeyHTTPSCORS - 7
Micro User Service API
Last check failedUser management and authentication. A free authentication & authorization API by m3o.com.
- HTTPS
apiKeyHTTPSNo CORS
Authentication & Authorization APIs compared
| API | API key | HTTPS | CORS | Uptime | Response | Rating |
|---|---|---|---|---|---|---|
| Auth0 | Required | Yes | Yes | Up | 583 ms | Not rated |
| Required | Yes | Yes | Up | 643 ms | Not rated | |
| Warrant | Required | Yes | Yes | Up | 926 ms | Not rated |
| Required | Yes | No | Up | 674 ms | Not rated | |
| Required | Yes | No | Up | 1903 ms | Not rated | |
| SAWO Labs | Required | Yes | Yes | Down | – | Not rated |
| Required | Yes | No | Down | – | Not rated |
More Authentication & Authorization APIs
Best Authentication & Authorization API FAQ
What is the best free Authentication & Authorization API in 2026?
Based on access, reliability and developer ratings, the top free Authentication & Authorization APIs right now are Auth0 API, MojoAuth API and Warrant API. Auth0 API ranks first. Rankings update daily from health checks of all 7 Authentication & Authorization APIs in the directory.
Which Authentication & Authorization API works from the browser?
Auth0 API, MojoAuth API and Warrant API support CORS over HTTPS, so front-end JavaScript can call them directly without a proxy.
How are these APIs ranked?
Each API gets a score from: no API key (+), HTTPS (+), CORS support (+), 30-day uptime and response time from our daily health checks, and ratings from developers on this site. APIs that failed three checks in a row are left out until they recover.