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Best API authentication platforms in 2026

API authentication platforms help applications verify users and control access to APIs. This list is for people choosing an authentication service or server on a budget.

  1. 1

    Amazon Cognito

    Free plan AndroidAPIiPhone+1

    Cognito combines application sign-in, federation, and access control with a wide set of AWS integrations.

    7.7 Free plan · paid from $0.01/user/mo Visit site
  2. 2

    Clerk

    Free plan AndroidAPIExtension+2

    Clerk combines authentication, user management, organization support, and billing for application teams, with a free Hobby tier and paid plans.

    7.6 Free plan · paid from $20/mo (annual) Visit site
  3. 3

    Curity Identity Server

    Free plan APILinuxMac+2
    7.5 Free plan · 14-day trial Visit site
  4. 4

    Descope

    Free plan AndroidAPIiPhone+2

    Descope combines visual authentication-flow design with SDKs, APIs, and a broad range of authentication methods.

    7.4 Free plan · paid from $249/mo (annual) Visit site
  5. 5

    Frontegg

    Free plan AndroidAPIiPhone+1

    Frontegg combines customer sign-in, authorization, and B2B tenant controls with developer SDKs and an embedded admin portal.

    7.3 Free plan Visit site
  6. 6

    FusionAuth

    Free plan AndroidAPIiPhone+5

    FusionAuth offers identity management with multiple authentication methods, standards, and deployment options.

    7.3 Free plan · paid from $162/mo (annual) Visit site
  7. 7

    Keycloak

    Free plan APILinuxSelf-hosted+2

    Keycloak provides single sign-on, multiple authentication methods, directory synchronization, and fine-grained authorization policies as open-source software.

    7.2 Open source Visit site
  8. 8

    Okta Customer Identity Cloud

    Free plan AndroidAPIiPhone+4

    Auth0 covers user sign-in, single sign-on, passwordless access, and machine-to-machine authentication, with developer tools and deployment options.

    7.0 Free plan · paid from $3,000/mo (annual) · 30-day trial Visit site
  9. 9

    Stytch

    Free plan AndroidAPIiPhone+1

    Stytch combines a broad set of identity, access-control, and fraud tools with implementation options for frontend and backend developers.

    6.9 Free plan Visit site
  10. 10

    LoginRadius

    Free trial AndroidAPIiPhone+2

    LoginRadius covers authentication, access management, integrations, and deployment choices for customer identity. The 14-day trial offers a way to evaluate it, while pricing requires a request.

    6.0 Pricing on request · 14-day trial Visit site
  11. 11

    Auth0

    by Okta, Inc.
    Paid WebAPI
    4.9 Visit site
  12. 12

    PingOne

    Paid Web

    PingOne covers workforce and customer identity workflows, with SSO protocols, adaptive access, MFA, and provisioning.

    4.1 From $3/user/mo (annual) · 30-day trial Visit site

#1Places #1, #2, #3, #4, #5 on this list can be bought by the makers of the software on it. See the price

Compare free plans, trial periods, paid pricing, supported platforms, and licence terms. Review each tool’s environment support—web, API, iOS, Android, self-hosted, or Linux—and its licence when code access or modification matters.

Questions

How does an API authentication platform work?

It is a service or server used by applications to verify users and control access to APIs.

Which platforms list a free plan?

Amazon Cognito, Auth0, Clerk, Curity Identity Server, Descope, Frontegg, FusionAuth, Keycloak, Okta Customer Identity Cloud, and Stytch are examples with listed free plans.

Which platforms list free trials?

Curity Identity Server and LoginRadius each list 14-day trials. Okta Customer Identity Cloud and PingOne each list 30-day trials.

Which option is open source?

Keycloak appears in the list as free and open source.

Where can these tools run?

This category covers tools for web, API, iOS, Android, self-hosted, and Linux environments. Check the platform label for the tool you want.

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