Popular OIDC Providers — Keycloak, Auth0, Okta, Azure AD Compared

In this tutorial, you will learn about Popular OIDC Providers. We cover key concepts, practical examples, and best practices to help you master this topic.

Choosing the right OIDC provider depends on your requirements for self-hosting, scalability, feature set, and budget. Keycloak offers open-source self-hosting, while Auth0, Okta, and Azure AD provide managed solutions with different strengths.

What You'll Learn

• How Keycloak, Auth0, Okta, and Azure AD compare as OIDC providers
• When to choose a self-hosted vs managed provider
• Key features to evaluate when selecting an OIDC provider

Why It Matters

Your choice of OIDC provider affects development velocity, operational cost, scalability, and Compliance. A startup might prefer Auth0 for quick integration, while an enterprise with strict data sovereignty might self-host Keycloak.

Real-World Use

DodaTech uses Keycloak for internal employee authentication (self-hosted for data control) and Auth0 for customer-facing social login (managed for scalability). This hybrid approach optimizes for both security and developer experience.

flowchart LR
    subgraph Self-Hosted
        K["Keycloak\nOpen Source"]
    end
    subgraph Managed
        A0["Auth0\nSaaS"]
        O["Okta\nEnterprise"]
        AD["Azure AD\nMicrosoft"]
    end
    K -->|"Full control"| D["DodaTech"]
    A0 -->|"Quick setup"| D
    O -->|"Enterprise SSO"| D
    AD -->|"M365 integration"| D
    style K fill:#dbeafe,stroke:#2563eb
    style A0 fill:#fef3c7,stroke:#d97706
    style O fill:#bbf7d0,stroke:#16a34a
    style AD fill:#fecaca,stroke:#dc2626

Provider Comparison

Keycloak Configuration

# Start Keycloak with Docker
docker run -p 8080:8080 \
  -e KC_BOOTSTRAP_ADMIN_USERNAME=admin \
  -e KC_BOOTSTRAP_ADMIN_PASSWORD=admin \
  quay.io/keycloak/keycloak:25.0.0 start-dev

# Keycloak OIDC client setup via admin API
import requests

admin_token = requests.post(
    "http://localhost:8080/realms/master/protocol/openid-connect/token",
    data={
        "client_id": "admin-cli",
        "username": "admin",
        "password": "admin",
        "grant_type": "password"
    }
).json()["access_token"]

client_payload = {
    "clientId": "doda-browser",
    "protocol": "openid-connect",
    "publicClient": True,
    "redirectUris": ["https://doda.example.com/*"],
    "standardFlowEnabled": True
}

create_client = requests.post(
    "http://localhost:8080/admin/realms/master/clients",
    json=client_payload,
    headers={"Authorization": f"Bearer {admin_token}"}
)
print(f"Client created: {create_client.status_code}")

Auth0 Configuration

// Auth0 SPA SDK configuration
import { createAuth0Client } from '@auth0/auth0-spa-js';

const auth0 = await createAuth0Client({
  domain: 'dodatech.us.auth0.com',
  clientId: 'abc123def456',
  authorizationParams: {
    redirect_uri: 'https://doda.example.com/callback',
    audience: 'https://api.dodatech.com',
    scope: 'openid profile email'
  }
});

// Login redirect
await auth0.loginWithRedirect();

// Handle callback
const result = await auth0.handleRedirectCallback();
const user = await auth0.getUser();
console.log('User profile:', user);

Azure AD Configuration

# Azure AD OIDC with MSAL library
from msal import ConfidentialClientApplication

app = ConfidentialClientApplication(
    client_id="your-client-id",
    client_credential="your-client-secret",
    authority="https://login.microsoftonline.com/your-tenant-id"
)

# Authorization URL
auth_url = app.get_authorization_request_url(
    scopes=["openid", "profile", "email"],
    redirect_uri="https://doda.example.com/callback"
)
print(f"Redirect user to: {auth_url}")

Common Mistakes

1. Choosing a Provider Before Defining Requirements

Evaluate provider features against your specific needs for social login, MFA, custom domains, and compliance before committing.

2. Ignoring Vendor Lock-In

Managed providers make it hard to migrate. Use standard OIDC protocols and avoid provider-specific extensions where possible.

3. Underestimating Self-Hosting Operations

Keycloak requires database management, backups, updates, and scaling. The operational cost of self-hosting often exceeds the license cost.

4. Not Testing the Free Tier Limits

Auth0's free tier has limits on active users and social login. Test against your projected scale before going to production.

5. Skipping Provider-Specific Documentation

Each provider has unique configuration requirements for logout, token lifetimes, and custom claims. Read their docs thoroughly.

Practice Questions

1. What is the main advantage of Keycloak over managed providers?
2. When would you choose Auth0 over Okta?
3. What is the primary difference between Azure AD and Azure AD B2C?
4. How does social login work in Keycloak?
5. What factors determine OIDC provider pricing?

Answers

1. Full control and no licensing cost. 2. Auth0 has a more developer-friendly free tier and simpler setup. 3. Azure AD is for employee identity; Azure AD B2C is for customer identity. 4. Configure identity provider federation (Google, Facebook, GitHub) in the Keycloak admin console. 5. Active users, social login providers, SSO integrations, and support level.

Challenge

Build a provider evaluation matrix that compares Keycloak, Auth0, Okta, and Azure AD across 15 criteria (pricing, features, compliance, etc.) and implements a scoring system to recommend the best provider based on weighted requirements.

FAQ

Mini Project

Create a Flask application that can authenticate users against any of the four OIDC providers via a configuration file. Include provider selection, token validation, user profile display, and a comparison dashboard showing the same user data from each provider.

What's Next

• Learn about OIDC testing strategies with mock providers
• Explore the complete OIDC project for a production implementation
• Continue to the next topic in the API authentication series