Best Open Source Alternatives to FusionAuth

Compare the best free and open-source alternatives to FusionAuth — self-hosted and desktop replacements you fully control, ranked by GitHub stars, license and platform support.

Curated by open-source.store · Updated November 2026 · 3 alternatives

FusionAuth

Proprietary SaaS

PricingFreemium

Platformsweb, linux, windows, macos

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FusionAuth alternatives compared

Open-source alternatives to FusionAuth, compared by stars, license and platform
Tool		License	Platforms	Self-hosted
Keycloak	37,657	Apache-2.0	LinuxDocker	Yes	Nov 2026	Visit
Zitadel	15,499	AGPL-3.0	LinuxDocker	Yes	Nov 2026	Visit
SuperTokens	15,340	Apache-2.0	LinuxDocker	Yes	Nov 2026	Visit

Top open-source FusionAuth alternatives

Keycloak37,657Apache-2.0

Keycloak is an open-source alternative to Okta and Auth0 that runs on your own infrastructure, providing self-hosted OIDC, SAML, and user federation.

LinuxDocker

vs FusionAuth: a free, open-source option you fully control, licensed Apache-2.0.

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Zitadel15,499AGPL-3.0

Open-source identity platform with native B2B multi-tenancy, Passkeys, event-sourced audit trails, and typed gRPC and REST APIs to replace Auth0.

LinuxDocker

vs FusionAuth: a free, open-source option you fully control, licensed AGPL-3.0.

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SuperTokens15,340Apache-2.0

SuperTokens is an open-source alternative to Auth0 that provides self-hosted authentication, customizable login SDKs, and local session verification.

LinuxDocker

vs FusionAuth: a free, open-source option you fully control, licensed Apache-2.0.

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Best Open Source Alternatives to FusionAuth

FusionAuth

FusionAuth alternatives compared

Top open-source FusionAuth alternatives

The modern standard for Protobuf workflows

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