Logto vs Authentik vs Zitadel: Open Source Identity Providers in 2026
The Identity Provider Cost Problem
Auth0 charges $23/month for up to 1,000 MAUs, scaling to $240+/month for larger user bases. Okta's pricing is custom but famously expensive at scale. AWS Cognito charges $0.0055 per MAU past 50,000.
Identity providers are infrastructure — not features — but they carry significant ongoing costs. The open source alternatives run on your own hardware with fixed infrastructure costs regardless of user count.
Three tools dominate the open source identity provider space in 2026: Logto for developer-focused SaaS products, Authentik for enterprise SSO and reverse proxy auth, and Zitadel for cloud-native B2B applications.
TL;DR
- Authentik (20K+ stars): Best enterprise identity provider. Application proxy, LDAP/RADIUS, SSO for everything. Most flexible.
- Zitadel (13K+ stars): Best for cloud-native B2B applications. Multi-tenancy, organizations, compliance features.
- Logto (12K+ stars): Best developer experience for SaaS apps. Clean API, management console, B2B organization support.
Quick Comparison
| Feature | Logto | Authentik | Zitadel |
|---|---|---|---|
| GitHub Stars | 12K+ | 20K+ | 13K+ |
| Primary use case | SaaS apps | Enterprise SSO | B2B cloud apps |
| Developer experience | Excellent | Good | Good |
| SAML | Yes | Yes | Yes |
| OIDC/OAuth2 | Yes | Yes | Yes |
| LDAP | Limited | Yes | Yes |
| RADIUS | No | Yes | No |
| Application proxy | No | Yes | No |
| Organizations/tenancy | Yes | Limited | Yes |
| Pre-built UI | Yes | Yes | Yes |
| Self-hosting | Easy | Medium | Medium |
| License | MPL-2.0 | MIT | Apache 2.0 |
Authentik — Best Enterprise Identity Provider
Authentik (20K+ GitHub stars) is the most versatile open source identity provider. Its standout feature is the application proxy: Authentik can act as a reverse proxy in front of applications, adding authentication to apps that don't support OAuth/SAML natively.
What Makes It Stand Out
Application proxy: This is Authentik's killer feature. Any internal web application — regardless of its native auth support — can be protected by Authentik. Users authenticate with Authentik, and only then can they access the proxied application. Add SSO to your internal Grafana, Kibana, GitLab, or any other tool.
Policy engine: Complex access policies with conditions: "Allow if group is 'DevTeam' AND login time is within business hours AND MFA is verified." Policy chains with multiple stages.
Flow system: Every authentication interaction is a customizable flow — stages, conditions, and branches. Customize login, password reset, enrollment, and device management flows.
Protocol breadth: SAML 2.0, OAuth2/OIDC, LDAP, RADIUS. Connect nearly any application or service.
LDAP outpost: Authentik can serve as an LDAP provider, letting older applications that only understand LDAP authenticate against your modern identity provider.
RADIUS: Support for VPN and network device authentication.
Self-Hosting
# Download docker-compose
wget https://goauthentik.io/docker-compose.yml
# Generate secrets
echo "PG_PASS=$(openssl rand -base64 36 | tr -d '\n')" >> .env
echo "AUTHENTIK_SECRET_KEY=$(openssl rand -base64 36 | tr -d '\n')" >> .env
docker compose up -d
Authentik runs as approximately 5 containers (server, worker, PostgreSQL, Redis, and optional GeoIP).
Use Cases
- SSO for all internal applications
- Add authentication to tools that don't support SSO natively (via proxy)
- Replace Active Directory for small-medium organizations
- VPN and network device authentication (RADIUS)
- Enterprise LDAP integration
Best for: IT administrators building SSO infrastructure for internal tools, organizations replacing Active Directory, and any deployment needing application proxying.
Zitadel — Best for Cloud-Native B2B Applications
Zitadel (13K+ stars) is designed for modern, cloud-native applications — particularly B2B SaaS products that need multi-tenant identity management and enterprise customer requirements like SAML and custom branding.
What Makes It Stand Out
Organizations (multi-tenancy): Zitadel has first-class multi-tenancy. Your enterprise customers can have their own organizations with their own IdP (bring your own SAML/OIDC), custom login pages, and member management. This is exactly what B2B SaaS needs.
Customer IdP integration: Enterprise customers can configure their Azure AD, Okta, or other IdP in Zitadel's organization settings. Their employees log in through their company's existing identity provider, creating SSO that spans multiple SaaS products.
Audit log: Immutable audit trail of all authentication events — critical for compliance (SOC 2, HIPAA, etc.).
Go-based efficiency: Single binary deployment (or Docker). Efficient resource usage.
Hosted login: Zitadel provides a polished hosted login page. Customize it with your brand.
Console UI: Admin console for user management, organization configuration, and application setup.
Self-Hosting
# Single binary
wget https://github.com/zitadel/zitadel/releases/latest/download/zitadel_linux_amd64.tar.gz
tar xvf zitadel_linux_amd64.tar.gz
./zitadel start-from-init --masterkey "$(openssl rand -base64 32)" \
--tlsMode disabled --config config.yaml
# Or Docker
docker run -d \
-p 8080:8080 \
-e ZITADEL_EXTERNALDOMAIN=auth.yourdomain.com \
-e ZITADEL_MASTERKEY="$(openssl rand -base64 32)" \
ghcr.io/zitadel/zitadel:latest start-from-init
Zitadel requires PostgreSQL (or CockroachDB for HA). Can run as a single container or multi-instance for high availability.
Use Cases
- B2B SaaS products needing enterprise SAML/SSO
- Applications requiring customer-configurable identity providers
- Compliance-heavy applications needing audit logs
- Multi-tenant applications with organization-level auth settings
Best for: B2B SaaS developers building products that enterprise customers need to configure with their own identity providers.
Logto — Best Developer Experience
Logto (12K+ stars) focuses on providing the best developer experience for adding auth to modern applications. The SDK design, management API, and self-hosting story are all optimized for application developers rather than IT administrators.
What Makes It Stand Out
Developer-first design: Logto's SDKs for React, Vue, Next.js, Express, and other frameworks are clean and well-documented. The auth integration pattern feels natural.
Management API: Comprehensive programmatic management of users, organizations, roles, and permissions. Build admin dashboards, automate user lifecycle, and integrate with your business logic.
Organizations (B2B): Create organizations, manage memberships, configure per-organization settings, and implement organization-level RBAC — all from a well-designed console.
Connector system: 40+ social and enterprise connectors (Google, Apple, GitHub, Azure AD, SAML IdPs) configurable through the console without code.
Webhooks: React to auth events (user registration, password change, organization creation) via webhooks.
Self-Hosting
curl -fsSL https://raw.githubusercontent.com/logto-io/logto/HEAD/docker-compose.yml | \
docker compose -p logto up -d
Single docker-compose command. Brings up Logto and PostgreSQL.
Logto Cloud: Managed service with free tier (50K MAUs). Self-host for unlimited users.
Best for: SaaS product developers who want the cleanest integration experience and comprehensive management API.
Choosing Between Them
The choice depends on your primary use case:
| Scenario | Recommended |
|---|---|
| SSO for internal tools | Authentik |
| Add auth to legacy apps without OAuth | Authentik (proxy) |
| LDAP/RADIUS integration | Authentik |
| B2B SaaS with enterprise customers | Zitadel |
| Multi-tenant customer-configurable SSO | Zitadel |
| Developer building a consumer or B2B SaaS app | Logto |
| Clean API + management console | Logto |
| Compliance + audit trails | Zitadel |
Cost Comparison
Auth0 Annual Costs
| MAUs | Monthly | Annual |
|---|---|---|
| 1,000 | $23 | $276 |
| 10,000 | $100+ | $1,200+ |
| 50,000 | $240+ | $2,880+ |
Self-Hosted
| Tool | Server (Hetzner) | Annual |
|---|---|---|
| Logto (CPX21) | $6.50/mo | $78 |
| Authentik (CPX31) | $10/mo | $120 |
| Zitadel (CPX21) | $6.50/mo | $78 |
For any meaningful user base (5,000+ MAUs), self-hosting saves $1,000+/year vs Auth0.
Find Your Identity Provider
Browse all Auth0 and Okta alternatives on OSSAlt — compare Logto, Authentik, Zitadel, Keycloak, and every other open source identity provider with deployment guides and feature comparisons.