Best Open Source Authentication Solutions in 2026
·OSSAlt Team
authenticationopen-sourceauth0comparison2026
Best Open Source Authentication Solutions in 2026
Auth0 costs $23+ per 1,000 MAU. Okta starts at $2/user/month. Here are the best open source auth platforms.
Quick Comparison
| Tool | Best For | License | Stars | Language |
|---|---|---|---|---|
| Keycloak | Enterprise SSO | Apache-2.0 | 23K+ | Java |
| Authentik | Modern proxy auth | MIT | 13K+ | Python/Go |
| Logto | Developer DX | MPL-2.0 | 9K+ | TypeScript |
| SuperTokens | Drop-in auth | Apache-2.0 | 13K+ | Java/Node |
| Ory | Cloud-native auth | Apache-2.0 | 14K+ | Go |
Key Differences
Keycloak — Enterprise Standard
- OIDC, SAML, LDAP, Kerberos
- User federation
- Fine-grained authorization
- Admin console
- Used by Red Hat, governments, enterprises
Authentik — Modern Proxy Auth
- Reverse proxy authentication (no code changes)
- Visual authentication flows
- SCIM provisioning
- Application proxy (outpost)
- Python/Django + Go
Logto — Best Developer Experience
- 15+ SDKs (React, Next.js, Vue, etc.)
- Beautiful sign-in UI
- Webhooks and audit logs
- Multi-tenant
- TypeScript-native
SuperTokens — Easiest Integration
- Pre-built UI components
- Session management
- Social login
- Email/password
- Passwordless
- Multi-tenancy
Choosing the Right Tool
| Need | Choose |
|---|---|
| Enterprise SSO (SAML/LDAP) | Keycloak |
| Protect existing apps (no code) | Authentik |
| Best SDK/DX | Logto |
| Drop-in React/Node auth | SuperTokens |
| Cloud-native microservices | Ory |
Cost Savings
| MAU | Auth0 | Self-Hosted Keycloak | Annual Savings |
|---|---|---|---|
| 1K | $276/year | $96/year (VPS) | $180 |
| 10K | $2,760/year | $192/year | $2,568 |
| 100K | $27,600/year | $384/year | $27,216 |
Compare all auth solutions on OSSAlt — protocols, SDKs, and pricing side by side.