Can I open-source Auth0?
YES · mature open-source replacementYes. Keycloak (28k stars), Better Auth (20k stars), Authentik (17k stars) are mature open-source replacements for Auth0 — self-host with real ops work and stop paying $70/mo.
Because authentication is the one system where a quiet mistake is a breach, and paying someone to own that is cheaper than owning it yourself.
xsomebody else being responsible when login breaks
xcompliance paperwork done for you
xanomaly detection and breached-password checks
xhosted MFA and passkey flows
xan upgrade path you did not have to test
These projects already replace it, free.
KKeycloakBattle-tested identity and access management server with SSO, OIDC/SAML, federation, and admin consoleopen source↗BBetter AuthFramework-agnostic TypeScript auth library that keeps users in your own database with plugins for 2FA, orgs, passkeysopen source↗AAuthentikFlexible self-hosted identity provider supporting OIDC, SAML, LDAP, and SCIM with a modern flow-based UIopen source↗What each one is, in full: Keycloak · Better Auth · Authentik
all 8 open-source alternatives to Auth0 →· no votes, no pay-to-list · just what's real
Can I open-source Auth0?
Yes. Keycloak replaces Auth0 today — self-host it on your own server or machine with no subscription. The full list of open-source alternatives is on this page.
How much does Auth0 cost?
Auth0 costs about $70/month (B2C Essentials), which is $840 per year. That's what you save by replacing it with open source.
What do I lose by replacing Auth0?
Honestly: somebody else being responsible when login breaks; compliance paperwork done for you; anomaly detection and breached-password checks; hosted MFA and passkey flows; an upgrade path you did not have to test. If any of those are load-bearing for you, keep paying.
Is there an open-source alternative to Auth0?
Yes: Keycloak (Battle-tested identity and access management server with SSO, OIDC/SAML, federation, and admin console) Better Auth (Framework-agnostic TypeScript auth library that keeps users in your own database with plugins for 2FA, orgs, passkeys) Authentik (Flexible self-hosted identity provider supporting OIDC, SAML, LDAP, and SCIM with a modern flow-based UI) All 8 curated open-source alternatives are at caniopensourceit.online/auth0/alternatives.