FirebaseComparisonBeginner · 4 min read

Firebase Auth vs Supabase Auth: Key Differences and When to Use Each

Both Firebase Auth and Supabase Auth provide user authentication services with easy integration, but Firebase offers more built-in providers and a mature ecosystem, while Supabase is open-source and offers SQL database integration. Choose Firebase for a robust, managed service and Supabase for flexibility and open-source control.

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Quick Comparison

Here is a quick side-by-side comparison of Firebase Auth and Supabase Auth based on key factors.

Factor	Firebase Auth	Supabase Auth
Type	Proprietary managed service by Google	Open-source backend with managed options
Authentication Methods	Email/password, social providers, phone, anonymous	Email/password, social providers, magic links
Database Integration	Works with Firebase Realtime Database and Firestore	Built-in PostgreSQL database integration
Customization	Limited backend customization	Full SQL and backend customization
Pricing	Free tier with usage limits, pay as you go	Free tier with generous limits, pay as you grow
Ecosystem	Large, mature with many Firebase services	Growing, open-source friendly ecosystem

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Key Differences

Firebase Auth is a fully managed authentication service tightly integrated with other Firebase and Google Cloud services. It supports many sign-in methods out of the box, including email/password, phone, and popular social providers like Google, Facebook, and Twitter. This makes it easy to add authentication quickly without managing backend infrastructure.

Supabase Auth is part of an open-source backend platform built on PostgreSQL. It supports email/password, social logins, and magic links, but its main strength is the deep integration with a SQL database, allowing developers to customize authentication flows and user data management with SQL and server-side logic. Supabase offers more backend control but requires more setup and understanding of SQL.

Firebase is ideal if you want a simple, scalable, and managed solution with a large ecosystem. Supabase is better if you want open-source flexibility, direct database access, and the ability to customize authentication deeply.

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Code Comparison

Here is how you sign up a user with email and password using Firebase Auth in JavaScript.

javascript

import { initializeApp } from 'firebase/app';
import { getAuth, createUserWithEmailAndPassword } from 'firebase/auth';

const firebaseConfig = {
  apiKey: 'YOUR_API_KEY',
  authDomain: 'YOUR_AUTH_DOMAIN',
  projectId: 'YOUR_PROJECT_ID'
};

const app = initializeApp(firebaseConfig);
const auth = getAuth(app);

async function signUp(email, password) {
  try {
    const userCredential = await createUserWithEmailAndPassword(auth, email, password);
    console.log('User signed up:', userCredential.user);
  } catch (error) {
    console.error('Error signing up:', error.message);
  }
}

signUp('test@example.com', 'securePassword123');

Output

User signed up: { uid: 'some-unique-id', email: 'test@example.com', ... }

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Supabase Auth Equivalent

Here is how you sign up a user with email and password using Supabase Auth in JavaScript.

javascript

import { createClient } from '@supabase/supabase-js';

const supabaseUrl = 'https://your-project.supabase.co';
const supabaseKey = 'YOUR_ANON_KEY';
const supabase = createClient(supabaseUrl, supabaseKey);

async function signUp(email, password) {
  const { data: user, error } = await supabase.auth.signUp({ email, password });
  if (error) {
    console.error('Error signing up:', error.message);
  } else {
    console.log('User signed up:', user);
  }
}

signUp('test@example.com', 'securePassword123');

Output

User signed up: { id: 'some-unique-id', email: 'test@example.com', ... }

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When to Use Which

Choose Firebase Auth when you want a quick, reliable, and fully managed authentication service with broad provider support and seamless integration with other Firebase services like Firestore and Cloud Functions.

Choose Supabase Auth when you prefer an open-source solution with direct SQL database access, need more backend customization, or want to avoid vendor lock-in while still having a managed option.

Firebase is best for fast development and scalability, while Supabase suits projects needing flexibility and control over the backend.

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Key Takeaways

Firebase Auth offers a mature, managed service with many built-in sign-in methods and tight Firebase integration.

Supabase Auth is open-source, built on PostgreSQL, and allows deep backend customization with SQL.

Use Firebase for quick setup and scalability with minimal backend management.

Use Supabase for flexibility, open-source control, and integrated SQL database access.

Both support email/password and social logins but differ in ecosystem and customization options.