What is FusionAuth?
FusionAuth is an authentication and authorization platform built to be dropped into an existing application rather than used only as a hosted SaaS. The free Community edition supports unlimited users and covers core OAuth2, OIDC, SAML, registration and MFA flows; paid Starter, Essentials and Enterprise plans add features like breach password detection, application theming, advanced MFA, SSO tenant management and managed hosting (FusionAuth Cloud).
Read the full overview
Sources checked 27 September 2026: official website, documentation, pricing.
Self-hostable, developer-first customer identity platform
Key capabilities
- Auth server: a self-hosted or cloud-hosted identity server with OAuth2, OIDC and SAML support.
- Prebuilt UI: customizable hosted login, registration and password-reset pages.
- SDKs: client libraries for major languages plus a documented REST API for user and tenant management.
Where FusionAuth fits
Customer identity and access management (CIAM): user registration and login, MFA and passwordless options, OAuth2/OIDC/SAML federation, and multi-tenant user management.
Positioning and limitations
FusionAuth fits teams that want to own their identity data and run auth on their own infrastructure rather than hand user records to a third-party SaaS. It competes with Auth0, Okta CIC and Keycloak for developer-facing customer identity, not with workforce-focused tools like Okta Workforce or Azure AD.
Because FusionAuth can run entirely on infrastructure you control, it suits teams with data-residency or compliance constraints that rule out a pure third-party identity SaaS, while the free Community tier still covers most core auth needs without a per-user fee.
“Self-hostable, developer-first customer identity platform”
Technical details
- Access
- Self-hosted
- Source model
- Commercial
- License
- Commercial
- Founded
- 2018
- Headquarters
- Broomfield, USA
- Pricing model
- Freemium
- Pricing details
- Software and service terms ↗
- API
- Available
- Website
- fusionauth.io ↗
What to verify
Start from the users, systems and operating responsibilities the tool needs to support.
- Confirm current features, licensing and support terms.
- Validate deployment, data location and access control.
- Test integrations, exports and recovery workflows.
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