9 Best Open-source Authentication Services

Authelia is a robust open-source authentication and authorization server designed for identity and access management (IAM). It provides single sign-on (SSO) capabilities and multi-factor authentication (MFA) for secure access to applications, all while integrating seamlessly with common reverse proxies.

1. Enterprise Security: Centralized IAM for business applications.
2. Web Applications: Secure user access management for online services.
3. Customizable Authentication Solutions: Tailored IAM for developers and IT teams.

Authentik is a powerful identity provider (IdP) and single sign-on (SSO) platform designed to provide secure, centralized access management across environments. It supports multiple authentication standards, including OAuth2, SAML, LDAP, and SCIM, allowing it to integrate seamlessly with various applications. With a user-friendly admin interface, Authentik simplifies user, group, and application management.

1. Centralized Authentication: Ideal for managing user access across applications with single sign-on.
2. Enterprise Security: Suitable for businesses needing robust authentication and MFA to protect data.
3. Customizable Access Control: Perfect for organizations requiring tailored login and access flows.

Keycloak is an open-source identity management platform that enables secure authentication, SSO, and role-based access control (RBAC) across multiple applications. With support for social logins, multi-factor authentication, and customizable login flows, Keycloak centralizes user management, making it easy to secure access without relying on third-party services.

1. Enterprise SSO Implementations: Securely manage logins across corporate apps.
2. Flexible Access Control: Customize permissions for users and roles.
3. Self-Hosted IAM Solutions: Organizations needing in-house identity management.

Ory provides a modern, modular identity and access management (IAM) solution designed for flexibility and scalability. It enables seamless integration with various applications through Single Sign-On (SSO), social logins, and passwordless authentication, all while offering customizable user interfaces and workflows.

1. Enterprise IAM: Central management of user identities and access.
2. Consumer Applications: Secure user authentication for customer-facing services.
3. Developer-Focused Solutions: Build tailored identity systems using APIs.

SuperTokens provides an open-source, self-hosted authentication solution focused on simplicity and scalability. It supports common authentication methods, including passwordless login, social login, and single sign-on (SSO), and integrates easily with existing applications. Designed to prevent vulnerabilities, SuperTokens offers comprehensive attack protection and ensures secure user access.

1. Custom Application Authentication: Tailored login for unique requirements.
2. Mobile and Web Apps: Adaptable login options across devices.
3. Enterprise Access Control: Centralized login management for internal apps.

Hanko is an open-source authentication and user management system that emphasizes modern, secure login methods. It facilitates the integration of passkeys—an advanced, passwordless authentication technology—into applications, enhancing both security and user experience. Additionally, Hanko supports email passcodes and offers optional password integration, catering to diverse security requirements.

1. Modern Web Applications: Ideal for applications seeking to implement cutting-edge authentication methods.
2. Mobile Applications: Enhances mobile user experience with seamless biometric authentication.
3. Enterprise Solutions: Offers scalable authentication for organizations aiming to adopt passwordless security.

Zitadel is a powerful identity management platform that simplifies authentication and authorization processes across applications. It supports various modern authentication methods, including Single Sign-On (SSO), social logins, and passwordless authentication, while offering a customizable hosted login page and robust APIs for seamless integration.

1. Enterprise Authentication: Centralized access management for businesses.
2. Consumer Applications: Secure user authentication for customer-facing services.
3. Developer-Centric Solutions: Customizable identity solutions for developers.

Appwrite is an open-source BaaS designed to help developers manage core backend functions such as user authentication, database management, and file storage without needing to set up extensive infrastructure. Built for both web and mobile applications, Appwrite supports a variety of front-end technologies and offers a self-hosted environment for greater data control. Its modular, RESTful API architecture allows developers to efficiently integrate key backend functionalities, making it easier to create robust, scalable applications.

1. Privacy-Focused Applications: Ideal for apps needing strict data control and compliance.
2. Custom Backend Logic: Build scalable server-side functions for complex workflows.
3. Self-Hosted Projects: Suitable for organizations requiring in-house backend hosting.

Supabase is an open-source backend-as-a-service (BaaS) that empowers developers with a PostgreSQL database, real-time data sync, and authentication out of the box. It offers SQL-based storage, allowing developers to use familiar SQL commands while benefiting from Supabase’s real-time API, enabling seamless updates across clients. With its authentication service, Supabase supports multiple authentication providers, making it simple to implement secure user management for web and mobile applications.

1. SQL-Based Projects: Ideal for projects requiring relational database structure.
2. Real-Time Applications: Build collaborative apps, chats, and live data dashboards.
3. Open-Source Development: Suitable for developers preferring open-source solutions.