#1
Keycloak is an open-source IAM server providing single sign-on, user federation, and centralized authentication and authorization using OIDC, OAuth 2.0, and SAML.
36.4k stars8.9k forksApache-2.0last commit Actively maintained
13 self-hosted Duo Single Sign-On alternatives
Cloud-based single sign-on service that provides SAML and OIDC authentication to SaaS and on‑premises applications, centralized access and authentication policies, and integration with Duo's multi‑factor and device‑trust controls for access management.
Alternatives to Duo Single Sign-On
#2
Authelia is an open-source IAM and authentication server providing SSO, MFA, and access control for web apps, with OpenID Connect/OAuth 2.0 and reverse-proxy integration.
28.7k stars1.5k forksApache-2.0last commit Actively maintained
Open-source IdP delivering SSO, OAuth2/OIDC, SAML2, LDAP, RADIUS, MFA, WebAuthn, conditional access and application-proxy capabilities for self-hosted deployments.
25.2k stars2k forkslast commit Actively maintained
OAuth2 Proxy is a reverse proxy and middleware that protects web apps with OAuth2/OIDC login and forwards authenticated user identity to upstream services.
14.9k stars2.2k forksMITlast commit Actively maintained
#5
ZITADEL is an open source IAM/CIAM platform providing SSO, MFA, OIDC/OAuth2, SAML, user management, and multi-tenant organizations with audit logging.
14.9k stars1.3k forksAGPL-3.0last commit Actively maintained
#6
Open-source authentication and authorization infrastructure with OIDC/OAuth 2.1, SAML SSO, multi-tenancy, MFA, and RBAC for SaaS and AI apps.
14.5k stars1.2k forksMPL-2.0last commit Actively maintained
#7
Casdoor is an open-source, UI-first IAM/SSO platform supporting OAuth 2.0, OIDC, SAML, LDAP, SCIM, WebAuthn and MFA, with an admin web UI and SDKs.
14.3k stars1.8k forksApache-2.0last commit Actively maintained
Pocket ID is a simple self-hosted OpenID Connect (OIDC) provider that lets users sign in to apps using passkeys instead of passwords.
9k stars304 forksBSD-2-Clauselast commit Actively maintained
#9
Tinyauth is a lightweight auth middleware that adds a login screen, OAuth, or LDAP authentication in front of your apps via common reverse proxies.
8.2k stars264 forksAGPL-3.0last commit Actively maintained
#10
Kanidm is a secure identity management platform providing SSO, passkeys (WebAuthn), and integrations like OAuth2/OIDC, RADIUS, and LDAP gateway for legacy apps.
5.3k stars354 forksMPL-2.0last commit Actively maintained
#11
A minimal, Rust-based forward authentication middleware for reverse proxies (Traefik, Caddy, nginx) using a passwd file and signed auth tokens.
157 stars8 forksMITlast commit Actively maintained
#12
Lightweight Go-based authentication gateway that provides unified SSO for Plex, Jellyfin, and Emby users with OIDC, MFA and an admin console. Runs in Docker and stores profiles in Postgres.
98 stars1 forksGPL-3.0last commit Actively maintained
#13
FusionAuth is a self-hosted authentication and IAM platform supporting OAuth2, OIDC and SAML, with SSO, MFA, user management and developer-focused integrations.
Activity unknown
What replacing Duo Single Sign-On actually involves
Every option on this page is open source and free to run on your own hardware, so you own the data and there is no subscription to cancel. 12 of 13 shipped a commit in the last six months. Licences in this list: Apache-2.0, MIT, AGPL-3.0, MPL-2.0, BSD-2-Clause. In exchange you take on hosting, backups and updates yourself.
Browse everything in Identity & Access Management (IAM).
