Single sign-on software offers a central login for all user accounts and IT systems. It modernizes the user experience by offering security and transparency.

Single Sign-On Software


Users in large organizations access digital resources seamlessly using Single Sign-On(SSO) software. Identity and access management using SSO software has become an integral part of routine business operations. In this blog post, we will go through some of the following top 5 popular open source single sign-on software.


IdentityServer is an open source free single sign-on software. It is a cross-platform framework based on OpenID Connect and OAuth 2. Further, this open source software provides central authentication and authorization capabilities for multiple applications. It supports federated identities, multiple flows, and API authorization. Moreover, this self hosting software enables users to login with a single set of usernames/passwords across many apps. However, IdentityServer is written in C# and all of its source code is available on Github along with documentation regarding deployment and development.

Following are the prominent features:

  • Claim-based Provider
  • Cross-Platform
  • UI Customization
  • Access Control for API
  • Single Sign-on /Sign-out

Learn more about IdentityServer


KeyCloak is another free software that is based on OpenID Connect, OAuth2.0, and SAML2.0. It provides SSO capabilities across web applications and web services. Above all, this open source software provides integrations with LDAP and Active Directory. There is a logical user interface where users can manage roles, permissions, and sessions. Moreover, this free solution provides client libraries for many languages such as Java, JavaScript, and C#. KeyCloak is mainly written in Java with little input from other languages such as JavaScript and HTML. Its source code is available on Github.

KeyCloak has the following key features:

  • Provides Client Adapters
  • User-Friendly UI
  • Authentication as Service
  • Integration With LDAP
  • Integration With Active Directory

Learn more about KeyCloak


CAS is open source SSO software with delegated authentication. Moreover, it is multilingual and comes up with central authorization services using the ticket-based protocol. This free software is built on client-server architecture. Central Authentication Service(CAS) supports many protocols such as OpenID, OAuth, OpenID Connect, REST, WsFederation, and SAML. Above all, there is a comprehensive system for integration with third-party apps. This single sign-on software is written in Java. However, its source code is available on Github with all documentation regarding development and deployment.

CAS offers the following important features:

  • Multilingual
  • Multifactor authentication 
  • Many Authorization Mechanisms (e.g. ABAC, Time/Date, REST )
  • UI To Manage Monitoring And Stats
  • Password Management

Learn more about CAS


Authelia is highly rich-featured and scalable SSO software. It offers great security and provides single sign-on and login regulation abilities. This open source software also provides support for LDAP and Active Directory. In addition, there is an intuitive user interface that lets users navigate easily. Further, it provides two-factor authentication based on Google Authenticator OTP. This free software works with a reverse proxy such as Nginx. However, Authelia is written in Go language and all its all source code is available on Github.

Authelia comes up with the following key features:

  • 2F Authentication with Yubikey
  • Identity verification
  • Block Brute Force Attacks
  • Works With Reverse Proxies
  • Push Notifications With DUO

Learn more about Authelia


WSO2 is another widely used open source identity and access management system. It supports almost all popular identity standards to provide authentication. It has exposed API end pints for the integration with other applications. WSO2 comes up with a user-friendly interface that is highly customizable. Moreover, this open source software also offers two-factor authentication. However, it is mainly written in Java and its all source code is available on Github with documentation regarding development and deployment.

WSO2 offers the following key points:

  • High Performance
  • Cloud Integrations
  • Flexible
  • Inbound/Outbound Provisioning
  • Identity Provider

Learn more about WSO2


Almost all of the open source SSO software mentioned in this blog post are widely used on enterprise level. If you are in process of choosing the best single sign on software for business then we recommend you to go through this article deeply.

Finally, is writing articles on further open source products. Therefore, please stay in touch with the Single Sign-on category for regular updates.