Open Source Okta Alternatives

Keycloak adds authentication to applications and secures services with minimal effort, so a team never has to store users or write a login flow of its own. Credentials, sessions and account recovery move out of the application entirely, which is where most of the security bugs in homegrown auth tend to live.

Beyond sign-in, the server covers user federation, strong authentication, user management and fine-grained authorization. The project publishes an operator package for Kubernetes and tracks open source best practice and security scorecard ratings in public, both of which matter for something sitting on the critical path of every login.

Running and working on the server follows a short set of paths.

• Distribution start: download a release, unzip it and run the kc script in development mode.
• Container start: the published image from the project registry starts the same way with one command.
• Building from source: a separate guide covers compiling the server for contributors.
• Testing: guides exist both for running the test suite and for writing new tests.
• Related projects: client libraries, quickstarts and a Node.js adapter live in their own repositories.

Help arrives through documentation, a mailing list for general questions and chat channels split between user help and design discussion, while security vulnerabilities follow a documented disclosure process instead of the public issue tracker. Contributors are asked to read the guide and the code of conduct first, and joining a maintainer area is offered as a way to shape where the project goes.

Single sign-on usually arrives as a hosted service with your directory inside it. Authentik is the identity provider you run yourself, sitting between users and every application they log into and issuing the assertion or token each one expects, so accounts live in one place instead of being duplicated across a dozen services.

Protocol coverage is the practical reason to reach for it. SAML, OAuth2 and OIDC serve modern web applications, while LDAP and RADIUS reach the older software and network equipment that never learned either. The same project is designed to scale from a small home lab to a large production cluster without changing tools along the way.

Installation follows the size of what you are running.

• Docker Compose: the recommended route for small and test deployments.
• Kubernetes: an official Helm chart is maintained for larger setups.
• AWS CloudFormation: official templates deploy the stack on AWS.
• DigitalOcean Marketplace: a one click app image for a quick managed host.
• Enterprise offering: a paid tier aimed at organizations replacing an existing provider such as Okta, Auth0, Entra ID or Ping Identity.

The repository carries separate licenses for the core, the website and the enterprise directory, so check which one covers the part you intend to modify. Developer documentation explains local build environments, testing your changes and the contribution process, and there is a dedicated security policy for reporting vulnerabilities rather than filing them as public issues.

Teams outgrow simple authentication the moment they start selling to other companies. ZITADEL is an open source identity and access management platform built for that point, giving SaaS products, B2B platforms and self-hosted stacks single sign on, MFA, passkeys, OIDC, SAML, SCIM and a multi-tenancy model in one deployment.

The architecture pairs a relational core with an event-driven design where every mutation is written as an immutable event, so the audit trail is a complete stream you can read through the API or push to outside systems with webhooks. Tenancy runs from the identity system down to organizations and projects, with isolated data and policy scoping at each level.

Everything the platform does is reachable over a typed interface.

• API-first surface: every resource and action is exposed over connectRPC, gRPC and HTTP JSON APIs.
• Authentication breadth: passkeys, OTP by app, email or SMS, LDAP, social and enterprise identity providers, and machine to machine flows.
• Actions: webhooks and custom code enrich tokens or run at defined points in a flow.
• Provisioning: a SCIM 2.0 server and role retrieval cover onboarding and authorization for enterprise customers.
• Self-service: registration with email and phone verification, an administration console, and branding set per organization.

Self-hosting runs on PostgreSQL 14 or newer and installs through Docker Compose or Kubernetes, with zero-downtime updates and no external session store to scale horizontally. The hosted service runs the same codebase, so moving between the two is not a change of product.

Ory Kratos lifts identity out of application code and puts it behind HTTP APIs. Login, registration, account recovery, verification and profile management become flows your services consume, rather than features every team rewrites once per product.

It is API first and interface agnostic, with both browser-based and native app flows, so any framework can drive it. Identity schemas and traits define what a user record holds, admin APIs cover lifecycle management, and the wider Ory stack adds OAuth2, OpenID Connect and access control when you need them.

Self-hosting is treated as a first-class path, not a courtesy.

• Platforms: installs on Linux, macOS, Windows and Docker, or builds from source.
• Databases: PostgreSQL, MySQL and CockroachDB are the supported stores.
• Kubernetes: deploying to Kubernetes and other orchestrators is covered in the install guide.
• Multi-factor: MFA belongs to the core flow set rather than arriving as an add-on.
• Migration path: pairing Kratos with Ory Hydra replaces the OAuth2 and OpenID Connect side of an existing provider while clients keep speaking the same protocols.

The open source distribution carries no license requirements and suits individuals, researchers and workloads that can live without an SLA. A managed equivalent runs the same server on the Ory Network, API compatible with what you would host yourself, for teams that would rather not operate identity infrastructure at all.

Defguard collapses the usual pile of disconnected tools for identity, VPN access, authentication and network permissions into a single self-hosted platform. Nothing leaves your infrastructure, and the architecture is arranged to keep the attack surface small.

Three components split the responsibilities, with network segmentation between them. Core is the management plane holding identity, authentication, authorization and policy. Edge is the public-facing entry point exposing selected services. Gateway enforces access policy in front of protected resources. The code is dual licensed, AGPL for the open core and a separate license for enterprise components.

The capabilities line up with what a security team has to prove.

• WireGuard VPN: multiple locations with per-location access control, MFA per connection, self-service device setup, and kernel or userspace operation.
• Identity and access management: an internal OIDC provider for single sign-on, external OIDC through Google, Microsoft or a custom provider, and LDAP or Active Directory sync.
• Multi-factor authentication: TOTP, WebAuthn and FIDO2, email tokens and biometrics through the mobile app.
• Firewall: allow and deny rules per location by user or group, applied in real time.
• Activity log: an audit trail with filtering and search, and real-time SIEM streaming in the enterprise build.
• Clients: desktop apps for Linux, macOS and Windows, plus Android and iOS with QR code onboarding.

A one-line installer brings up an instance in minutes, though the documentation is blunt that it suits testing and evaluation only. Production work follows separate architecture and high-availability guidance, alongside published SBOMs, penetration test reports and architecture decision records.