Target product
Auth0
Auth0 is often the default benchmark for authentication infrastructure. Open source alternatives usually compete on self-hosting, cost control, and stack flexibility.
Alternatives ranked
4
Categories
1
Hosting model
Cloud available
Current page
Auth0
Why this page exists
Teams rarely search for open source alternatives to Auth0 just because they want something “free.” The real reasons are usually more specific: hosting control, privacy requirements, budget pressure, integration flexibility, or the need for a product that fits a more developer-first workflow. That is why this page ranks the alternatives instead of just listing them alphabetically.
The goal here is to make the decision easier to reason about. Some replacements are strongest when you want a self-hosted stack. Others are better when you need a modern developer experience, a privacy-first posture, or a tighter fit for product and operations teams. The best alternative depends on what you are optimizing for, not just on which tool has the most recognizable name.
Mature open source IAM with SSO and federation.
Keycloak is one of the most established open source Auth0 alternatives for self-hosted identity.
Best for
Teams needing enterprise-style identity with self-hosting.
Limitations
Heavier to operate than developer-first hosted auth.
Repository activity
Repository profile
Modern open source identity platform with flexible deployment.
ZITADEL is a strong Auth0 alternative for teams wanting a modern identity stack with open source roots.
Best for
Teams that want self-hosted or managed identity without a classic enterprise footprint.
Limitations
Smaller ecosystem than older incumbents.
Repository activity
Repository profile
Open source authentication for modern apps.
Developer-friendly app auth with self-hosting.
SuperTokens is a practical Auth0 alternative when app authentication matters more than enterprise IAM breadth.
Best for
Application teams focused on login, sessions, and auth flows.
Limitations
Narrower than full IAM platforms.
Repository activity
Repository profile
Self-hosted identity provider with strong admin flows.
Authentik is a strong self-hosted option when your auth problem looks like identity infrastructure.
Best for
Teams building internal or self-managed identity workflows.
Limitations
Different fit from app-auth SDK-first products.
Repository activity
Repository profile
Developer-focused auth and user management.
Hosted auth product with polished developer workflows and UI components.
Authentication for Firebase apps.
Hosted auth service that integrates closely with the Firebase ecosystem.
Enterprise identity and access management.
Enterprise IAM platform used for workforce identity, SSO, and access management.
FAQ
The most common reasons are cost control, self-hosting, data ownership, privacy, stack flexibility, and the ability to customize or extend the product without waiting on a vendor roadmap. The right replacement depends on whether your biggest concern is hosting model, feature depth, developer experience, or long-term portability.
Usually five to eight is the right range. That is enough to surface real tradeoffs without flooding the page with weak filler options. A narrower set of credible alternatives is much more useful than a giant unranked list.
Not always. Some open source products also offer managed cloud hosting, and some open-core products combine open source code with paid hosted features. That is why this page keeps the hosting model visible instead of treating open source and self-hosted as the same thing.
