Authentik vs. Zitadel 2026: Open-Source Identity Provider Comparison

If you're looking for an Okta or Auth0 alternative, two open-source projects quickly rise to the top: Authentik and Zitadel. Both solve the same problem – centralized identity & access management – but with fundamentally different approaches.

💡 Managed Authentik from €34.90/mo – your own instance, unlimited users, hosted in Germany. GDPR-compliant, 24/7 monitoring. Start 7-day free trial →

In this comparison, we show how they differ and which identity provider fits which use case.

Further resources:

• → authhost.de – Managed Authentik from €34.90/mo
• → Authentik Expertise at WZ-IT
• → Keycloak Managed Hosting

Table of Contents

• Quick Overview
• Architecture and Technology
• Protocols and Integrations
• Multi-Tenancy
• Self-Hosting
• Licensing
• Pricing
• Security and Compliance
• Community and Ecosystem
• When to Choose Which
• Our Approach at WZ-IT

Quick Overview

Architecture and Technology

Authentik: Python Hybrid with Flow Engine

Authentik is written in Python (backend) with a TypeScript frontend. The architecture consists of multiple services: server, worker and PostgreSQL. Redis was removed in version 2025.10 and replaced by PostgreSQL-based task processing.

The core innovation is the Flow Engine: authentication processes are modeled as configurable flows with stages, policies and providers. This allows extremely flexible login processes – from simple username/password to complex conditional access scenarios.

Authentik can simultaneously function as an Identity Provider, an LDAP Server and a Forward-Auth Proxy. This makes it particularly valuable for environments with legacy applications that lack native SSO support.

Zitadel: Go Binary with Event Sourcing

Zitadel is written entirely in Go and runs as a single binary. The architecture is based on event sourcing with a relational database (PostgreSQL or CockroachDB) as backend.

The approach is cloud-native and Kubernetes-first: horizontal scaling, gRPC APIs and a Kubernetes operator are built in from the start. This makes Zitadel ideal for modern infrastructure, but introduces an HTTP/2 requirement for the reverse proxy – which can be problematic with Cloudflare Tunnels or similar setups.

Key difference: Authentik is more flexible and can serve more protocols. Zitadel is leaner and scales better horizontally.

Protocols and Integrations

Why Proxy Mode Can Be Decisive

Authentik's proxy mode is a genuine differentiator. It allows putting SSO in front of applications that don't speak OIDC or SAML natively – via forward-auth or reverse proxy integration. For self-hosters with tools like Portainer, Grafana (without integrated SSO), or older web applications, this is invaluable.

Zitadel offers no proxy mode. Applications must natively support OIDC or SAML.

Multi-Tenancy

This is where the paths diverge:

Zitadel was built from the ground up for multi-tenancy. The hierarchy is: Instance > Organization > Project > Application. Each organization can have its own branding, security policies, identity providers and user management. This is ideal for B2B SaaS platforms that need to onboard customer organizations.

Authentik can handle multi-tenancy, but it's not a core feature. For simple scenarios it works fine, for complex multi-tenant setups with strict isolation between tenants, Zitadel is the better choice.

Self-Hosting

Authentik

• Deployment: Docker Compose or Kubernetes (Helm chart)
• Complexity: Medium (multiple services)
• Resources: ~300 MB RAM idle, ~500 MB Docker image
• Upgrades: Caution required – users report breaking changes with major upgrades (2025.4, 2025.12, 2026.2). Downgrades are not supported. Database backup before every upgrade is mandatory.

Zitadel

• Deployment: Single binary, Docker Compose or Kubernetes (Helm chart + operator)
• Complexity: Low (one binary + database)
• Resources: ~100 MB RAM idle, ~50 MB Docker image
• Caveat: Requires HTTP/2 on the reverse proxy for gRPC APIs. Not all proxies/tunnels support this out of the box.

Licensing

Why this matters: For companies that want to embed or modify the identity provider, Authentik's MIT license is significantly more permissive. Zitadel's AGPL 3.0 means: if you modify the code and offer it as a service, you must disclose the changes – or purchase an enterprise license.

Pricing

Authentik

Zitadel

Bottom line: Authentik's free version has no user limits and includes almost everything. Zitadel's free cloud version is capped at 100 Daily Active Users. For self-hosting, both are free.

Security and Compliance

Zitadel, as a Swiss company, has a strong focus on compliance and is ISO 27001 and SOC 2 certified. Authentik has no own certification but can be run on certified infrastructure.

Community and Ecosystem

Authentik has the larger community (~20,700 GitHub stars) and more integrations. Documentation is comprehensive and covers many self-hosting scenarios. The Flow Engine allows customizations that aren't possible with other providers.

Zitadel has a smaller but active community (~13,400 stars). API documentation is excellent, and the Terraform provider is one of the best in the IAM space. The Zitadel team (Switzerland) is active in discussions and responsive to feature requests.

What the Community Says

From a popular Reddit thread (r/selfhosted):

"Zitadel is certainly better in terms of built-in multi-tenancy. The API is way more adequate, along with its Terraform provider. With Authentik, upgrades tend to break my existing integrations like LDAP workers."

"Authentik's proxy mode is irreplaceable when you have apps without native SSO support."

When to Choose Which

Choose Authentik when:

• Legacy applications without OIDC/SAML need to be integrated (proxy mode)
• LDAP server functionality is needed (e.g., as AD replacement)
• RADIUS or Kerberos are required
• The most permissive license is desired (MIT)
• Maximum flexibility in authentication flows is needed
• Running a homelab or mid-size self-hosted setup

Choose Zitadel when:

• Building a B2B SaaS platform with multi-tenant customer onboarding
• A lightweight, Kubernetes-native identity server is needed
• API-first development is prioritized (Terraform, gRPC)
• Minimal resource footprint matters
• Horizontal scalability for millions of users is planned
• ISO 27001 / SOC 2 certification of the provider is relevant

Consider Keycloak when:

• The most mature, battle-tested enterprise IAM is needed
• Java EE ecosystem integration is important
• Maximum protocol support is required

Managed Authentik with authhost

Don't want to self-host Authentik? authhost is our managed hosting service for Authentik – your own instance, fully managed, hosted in Germany.

What you get:

• Dedicated Authentik instance in German data centers
• SSO, MFA, LDAP, SCIM, RADIUS, Proxy – all included
• 24/7 monitoring, automatic updates and security patches
• No per-user fees, no setup fees
• 7-day free trial – no credit card required

authhost.de – Start 7-day free trial →

Further Guides

• authhost.de – Managed Authentik Hosting
• Authentik at WZ-IT
• Keycloak Managed Hosting
• birdhost.de – Managed NetBird VPN
• All Security Expertises