Auth0 Alternatives 2026: 7 Free Options
Auth0 alternatives: Keycloak, ZITADEL, Clerk, Supabase and 3 more. Prices and licenses checked October 22, 2026.
•4 min read•Passwords, Privacy & Identity
Verdict:Auth0's free plan allows up to 25,000 monthly active users, but the first paid tier is steep: B2C Essentials is $35 a month for only 500 MAU, and the B2B version is $150. That jump is the usual reason people leave. If you want to pay nothing per user, the realistic options are self-hosted: Keycloak is mature, Apache-2.0 and supports SAML and OIDC, but it asks for real operational effort. ZITADEL is newer and easier to run, though it is AGPL-3.0. Better Auth keeps everything inside your own TypeScript codebase and database, which is the cheapest route if your login needs are standard. For hosted services with larger free tiers than Auth0, Clerk and Supabase both give 50,000 users, and Firebase Authentication gives 50,000 too. Pick Clerk when you want polished prebuilt UI, Supabase when you also need Postgres, and Firebase when the rest of your app is already on Google Cloud. The trade-off is migration: password hashes can usually be exported from Auth0 only through a support request, and social-login identities, MFA enrollments and custom rules do not carry over automatically. Plan to ask users to reset passwords or run both systems side by side during the move. Also check whether you depend on enterprise SAML connections, which are often a paid feature elsewhere.
Quick comparison
| Tool | Price | Platforms | Best for | Tested |
|---|---|---|---|---|
| Keycloak | Free (free open source; you host and run it) | Self-hosted | Teams that can host their own identity server | Docs only |
| ZITADEL | Free (cloud Free tier: 100 daily active users, unlimited users); paid from $100 per month (Pro, 25,000 daily active users) | Self-hosted, Web | Self-hosters who want a modern open-source option | Docs only |
| Clerk | Free (Hobby plan: 50,000 monthly retained users per app); paid from $20 per month, billed annually (Pro; $25 billed monthly) | Web API | React and Next.js apps needing drop-in UI | Docs only |
| Supabase | Free (Free plan: 50,000 monthly active users for Auth, 500 MB database, 2 active projects); paid from $25 per month (Pro, 100,000 MAU) | Web, Self-hosted | Apps that also need a database | Docs only |
| Firebase Authentication | Free (no cost up to 50,000 monthly active users (50 for SAML/OIDC)) | Web API | Mobile apps already on Google's stack | Docs only |
| Better Auth | Free (free library; users and sessions live in your own database) | TypeScript | TypeScript apps that want auth in their own code | Docs only |
| Kinde | Free (10,500 monthly active users included); paid from $25 per month (Pro) | Web API | Startups wanting simple hosted auth | Docs only |
| Okta | Paid from $6 per user/month, billed annually (Workforce Identity Starter Suite; $1,500 annual contract minimum) | Web (SaaS) | Identity and access management | Docs only |
| Microsoft Entra ID | Free (Entra ID Free: MFA, unlimited SSO and password self-service; requires an Azure subscription); paid from $7 per user/month, billed annually (Entra ID P1) | Web (SaaS) | Identity and access management | Docs only |
Independent comparison. Paid placements are labelled separately; editorial links earn no affiliate commissions. Learn more.
Good fit if
- You can host it and want no per-user fee (Keycloak is the pick)
- You build with React and want prebuilt login screens (Clerk is the pick)
- You also need a Postgres database (Supabase is the pick)
- Your app is TypeScript and you want auth in your own code (Better Auth is the pick)
- Your app already runs on Google Cloud (Firebase Authentication is the pick)
Not ideal if
- You rely on Auth0 features or integrations that these tools do not replicate
Auth0 today: Free (up to 25,000 monthly active users); paid from $35 per month (B2C Essentials, 500 MAU; B2B Essentials is $150) (Auth0 pricing, checked 2026-10-22).
Why people look for Auth0 alternatives
Auth0's Free plan covers up to 25,000 monthly active users, but paid B2C pricing climbs with each MAU tier: Essentials is $35 a month at 500 MAUs, $700 at 10,000 and $1,400 at 20,000. B2B Essentials starts at $150 and Professional at $800 a month. Enterprise SSO connections beyond the included 3 or 5 cost $100 a month each, and Enterprise MFA is a $100 monthly add-on on B2B Essentials.
Keycloak
Compared with Auth0: Keycloak is Apache-2.0 and free to self-host, with SSO, OpenID Connect and SAML 2.0. You pay no per-user fee, unlike Auth0 after 25,000 MAU. You also run, patch and scale it yourself, and the admin interface is plainer than Auth0's.
Price: Free (free open source; you host and run it) (Keycloak pricing, checked 2026-10-22).
Platforms and license: Self-hosted. Apache-2.0 (open source).
Project activity: 37.6k GitHub stars · latest release 26.8.1 (Oct 13, 2026) · last commit Oct 27, 2026
Best for: Teams that can host their own identity server.
Worth knowing: Supports SSO, OpenID Connect, OAuth 2.0 and SAML 2.0 per the project site. CNCF incubating project.
ZITADEL
Compared with Auth0: ZITADEL is AGPL-3.0 and its cloud Free tier covers 100 daily active users, far below Auth0's 25,000 MAU. Pro is $100 a month for 25,000 daily users. You gain self-hosting and unlimited users; AGPL may matter for your legal team.
Price: Free (cloud Free tier: 100 daily active users, unlimited users); paid from $100 per month (Pro, 25,000 daily active users) (ZITADEL pricing, checked 2026-10-22).
Platforms and license: Self-hosted, Web. AGPL-3.0 (open source).
Project activity: 15.5k GitHub stars · latest release v4.20.0 (Oct 22, 2026) · last commit Oct 27, 2026
Best for: Self-hosters who want a modern open-source option.
Clerk
Compared with Auth0: Clerk's Hobby plan covers 50,000 monthly retained users, double Auth0's 25,000 MAU free limit, and Pro is $20 a month billed annually. You get prebuilt React components; you lose some enterprise SSO depth and flexibility.
Price: Free (Hobby plan: 50,000 monthly retained users per app); paid from $20 per month, billed annually (Pro; $25 billed monthly) (Clerk pricing, checked 2026-10-22).
Platforms and license: Web API. Proprietary.
Best for: React and Next.js apps needing drop-in UI.
Worth knowing: Billed on monthly retained users: a user counts only if they return at least one day after signing up.
Supabase
Compared with Auth0: Supabase Auth includes 50,000 MAU on the Free plan, and Pro is $25 a month with 100,000 MAU. It comes bundled with a Postgres database, which helps if you need one anyway, but free projects pause after a week of inactivity.
Price: Free (Free plan: 50,000 monthly active users for Auth, 500 MB database, 2 active projects); paid from $25 per month (Pro, 100,000 MAU) (Supabase pricing, checked 2026-10-22).
Platforms and license: Web, Self-hosted. Proprietary.
Best for: Apps that also need a database.
Worth knowing: Free projects pause after 1 week of inactivity.
Firebase Authentication
Compared with Auth0: Firebase Authentication is free up to 50,000 MAU (only 50 for SAML or OIDC), twice Auth0's free tier. It ties you to Google Cloud; check its pricing page for rates beyond the free tier.
Price: Free (no cost up to 50,000 monthly active users (50 for SAML/OIDC)) (Firebase Authentication pricing, checked 2026-10-22).
Platforms and license: Web API. Proprietary.
Best for: Mobile apps already on Google's stack.
Worth knowing: Beyond the free tier, Google Cloud Identity Platform pricing applies; phone auth is billed per SMS.
Better Auth
Compared with Auth0: Better Auth is an MIT TypeScript library, so there is no vendor bill and users stay in your own database. Compared with Auth0 you lose a hosted login service and its admin dashboard, and take on security updates yourself.
Price: Free (free library; users and sessions live in your own database) (Better Auth pricing, checked 2026-10-22).
Platforms and license: TypeScript. MIT (open source).
Project activity: 30.5k GitHub stars · latest release v1.7.14 (Oct 26, 2026) · last commit Oct 27, 2026
Best for: TypeScript apps that want auth in their own code.
Kinde
Compared with Auth0: Kinde's free plan includes 10,500 MAU and Pro is $25 a month, so it gives less free headroom than Auth0's 25,000. You get a simpler developer experience and pricing; Auth0's enterprise connections and ecosystem are broader.
Price: Free (10,500 monthly active users included); paid from $25 per month (Pro) (Kinde pricing, checked 2026-10-22).
Platforms and license: Web API. Proprietary.
Best for: Startups wanting simple hosted auth.
Other popular options (paid)
Okta
Compared with Auth0: Customer Identity Enterprise starts at $3,000 per month billed annually, not per user. Workforce Identity Starter Suite is $6 per user per month with a $1,500 annual contract minimum, so it targets larger buyers than Auth0's self-serve tiers.
Price: Paid from $6 per user/month, billed annually (Workforce Identity Starter Suite; $1,500 annual contract minimum) (Okta pricing, checked 2026-10-22).
Microsoft Entra ID
Compared with Auth0: Entra ID Free includes MFA, unlimited SSO and self-service password reset but requires an Azure subscription; P1 is $7 per user per month billed annually. Check it covers customer-facing login needs before switching.
Price: Free (Entra ID Free: MFA, unlimited SSO and password self-service; requires an Azure subscription); paid from $7 per user/month, billed annually (Entra ID P1) (Microsoft Entra ID pricing, checked 2026-10-22).
Which one to pick
- You can host it and want no per-user fee: Keycloak
- You build with React and want prebuilt login screens: Clerk
- You also need a Postgres database: Supabase
- Your app is TypeScript and you want auth in your own code: Better Auth
- Your app already runs on Google Cloud: Firebase Authentication
Limits of this review
Docs-only for Keycloak, ZITADEL, Clerk, Supabase, Firebase Authentication, Better Auth, Kinde: we did not install or run them, so feature claims come from vendor pages and we did not test import from Auth0. Vendor prices and free limits change; confirm on the linked pricing page before you buy or migrate.
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Kevin Fan
Kevin Fan is a SaaS founder. He runs Free Instead Of, which tracks free and open-source alternatives to paid software and checks each price and free-plan limit against the vendor's own pages.
Methodology
Based on official pricing and product pages checked 2026-10-22: Auth0, Keycloak, ZITADEL, Clerk, Supabase, Firebase Authentication, Better Auth, Kinde, Okta, Microsoft Entra ID. Prices, free limits and licenses are the figures shown on those pages on those dates. No tool on this page was installed or run. No accounts were created.