Intro

When building a SaaS application, one of the first things you need to get right is authentication. Without secure and user-friendly sign-ins, your app could lose trust and fail to scale. But with so many options out there, choosing the right authentication tool can be a headache. Two of the most popular open-source solutions are Supabase and Keycloak. Each of these tools is great, but they serve different audiences and needs.
So, how do you choose the right one for your app? Let’s break it down.

What Are We Choosing Between?

In simple terms, we’re comparing two authentication solutions that help you handle who gets access to your app and what they can do inside it. Both Supabase and Keycloak let you manage users and control access to resources, but how they do it, and for who, can vary a lot.

Who Are You Building For?

Before diving into the nitty-gritty, it’s important to consider who your audience is. Are you building a B2C (business-to-consumer) SaaS platform or an enterprise-grade B2B app? This question matters because Supabase and Keycloak are optimized for different types of users.

Supabase vs. Keycloak(Preview)

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I. Keycloak: The Ops Friendly

Keycloak is the heavyweight in this comparison. Built for enterprise-grade security, Keycloak offers robust features like Single Sign-On (SSO), identity brokering, and deep role-based access control (RBAC). It is an open-source Identity and Access Management tool that provides robust features for managing user authentication and authorization. It is widely used in SaaS architectures due to its flexibility, scalability, and support for modern authentication standards.

📒Documentation: Keycloack guides

Why Keycloak is Suitable for Your SaaS

1. Support for Modern Protocols

Keycloak supports modern authentication protocols essential for features like single sign-on (SSO), and token-based authentication for APIs like:

• OAuth2 and OpenID Connect (OIDC) for secure user login and authorization flows.
• SAML for integrating with enterprise identity providers.

2. Multi-Tenancy Support

In a SaaS environment, where different organizations (tenants) access your application:

• Keycloak allows you to configure realms, which are isolated spaces for managing users, roles, and clients.
• Each tenant can have its own realm, making it easier to segregate authentication data.

3. Flexible User Federation

Keycloak can integrate with external user stores, if your SaaS needs to support existing user bases or enterprise clients with their own identity providers. such as:

• LDAP or Active Directory.
• Database user tables.

4. Built-in Features

Keycloak provides many features out-of-the-box, saving development time:

• Login Pages: Fully customizable templates for your SaaS branding.
• Role-Based Access Control (RBAC): Manage permissions at a fine-grained level.
• Social Login: Support for third-party login via Google, Facebook, GitHub, etc.
• Session Management: Handle user sessions effectively with idle and max session limits.

5. Extendibility

For additional functionalities. Keycloak can be extended via Custom SPI (Service Provider Interfaces) & its REST API for managing users, sessions, and tokens.

Keyloack Integration with Your SaaS

To integrate Keycloak into your SaaS

1. Deployment Options

• Host it yourself: Use Docker, Kubernetes, or OCI to deploy Keycloak.
• Managed Services: Some cloud providers and third parties offer hosted Keycloak solutions.
  • Skycloak.io
  • Elestio ($15/mo for 2CPU/4GB/40GB)
  • cloud-iam
  • phasetwo.io & bare.id
    

2. Connect Your App:

• Register your SaaS application as a client in Keycloak.
• Configure the redirect URIs for login and logout.
• Use Keycloak’s OIDC SDKs or REST APIs to handle authentication in your app.

3. Secure Your APIs

• Protect your backend endpoints using Bearer Tokens issued by Keycloak.
• Validate tokens in your backend to restrict access to authenticated users.

Pros & Cons

Pros

Cons

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II. Supabase: The Startup Hero

Supabase is an open-source backend-as-a-service (BaaS) that’s often called the “open-source Firebase alternative”. It’s ideal for developers who need an easy way to handle authentication without the complexity. Supabase offers a fully managed authentication system that integrates OAuth, social logins, and even email/password authentication. Its easy-to-use UI and seamless integrations with Google, GitHub, and other social media providers.

Supabase is built with developers in mind designed for rapid development, offering a rich developer experience with clear documentation, intuitive UI, and rapid development capabilities.

📒Documentation: Auth guides

Why Supabase is Suitable for Your SaaS

1. Ease of Use and Quick Setup

Supabase is perfect for developers looking to launch a SaaS quickly. It provides a simple, out-of-the-box authentication solution with minimal configuration and pre-built UI components.

2. Integrated Backend:

Combines authentication with a powerful PostgreSQL backend and real-time APIs for seamless data management and user authentication.

4. Real-Time Features

Supabase supports real-time subscriptions, making it easy to build apps that need real-time user session updates or collaborative features.

5. Role-Based Access Control (RBAC)

Supabase offers RBAC tied directly to the database rows through PostgreSQL Row-Level Security (RLS). This allows fine-grained access control, ensuring that only the right users have access to specific data based on their roles.

6. Multi-Tenancy (Basic)

Supabase supports basic multi-tenancy through schema separation and role segregation at the database level. This allows you to segregate user data by tenants, even though it might not offer the same isolation as a Keycloak realm.

7. Support All the social providers

Enable social logins with a click of a button. Google, Facebook, GitHub, Azure, Gitlab, Twitter, Discord, and more.
All user data (accounts, access policies, etc…) is stored and managed in the database backend.

See Supabase CEO‘s Auth presentation below…

Supabase Integration with Your SaaS

Adding Supabase to your SaaS application is a straightforward process:

1. Deployment Options
   • Fully Managed Hosting: Supabase handles infrastructure, offering a fully hosted platform.
   • Self-Hosting: Supabase is also deployable via Docker or Kubernetes.
2. Sign Up and Set Up a Project: Create a project on Supabase and configure your authentication settings.
3. Connect Frontend & Backend: Use the client library to link your app’s frontend to its authentication & DB services.
4. Customize Authentication: Set up social logins, email/password, or magic link authentication.
5. Implement Access Control: Leverage PostgreSQL’s row-level security (RLS) to enforce RBAC to your app’s data.
6. Enhance : Enable live session updates or real-time event triggers for enhanced user experience.

Pros & Cons

Pros:

Cons

Summary

Choose Supabase If:

Choose Keycloak If:

Final Thoughts

Choosing the right IAM solution depends on your organization’s size, security needs, and authentication complexity:

If your SaaS application is geared toward larger regulated organizations or complex authentication, Keycloak is the way to go. For straightforward use cases or rapid deployment for Fast time-to-market, Supabase wins.

Note: We might extend this review series to other solutions in the future (i.e Authelia, Authentic ..)

Stay Tuned!