Supabase vs Firebase 2026: 완전 비교 — PostgreSQL vs NoSQL

Supabase and Firebase are the two most popular Backend-as-a-Service (BaaS) platforms in 2026, but they represent fundamentally different philosophies. Supabase is an open-source PostgreSQL-based platform that gives you a full relational database with SQL power, while Firebase is Google's proprietary NoSQL platform optimized for rapid prototyping and mobile-first applications. This guide compares every aspect — database architecture, authentication, storage, realtime capabilities, pricing, security, and more — with real code examples to help you make the right choice.

Philosophy and Architecture

The core difference between Supabase and Firebase comes down to open source relational vs proprietary NoSQL. Supabase wraps existing open-source tools — PostgreSQL, GoTrue, PostgREST, Realtime, and Storage — behind a unified API. You own your data and can migrate or self-host at any time.

Firebase is a collection of Google Cloud services (Firestore, Authentication, Cloud Functions, Hosting, Cloud Storage) presented through client SDKs. It is deeply integrated with the Google Cloud ecosystem, offering services like Analytics, Crashlytics, Remote Config, and ML Kit that have no Supabase equivalent.

Database: PostgreSQL vs Firestore

This is where the two platforms diverge most dramatically. Supabase gives you a full PostgreSQL database with all the power of SQL — JOINs, aggregations, window functions, CTEs, full-text search, and extensions like PostGIS for geospatial data. Firestore is a document-oriented NoSQL database where data is stored as collections of documents with nested subcollections.

Here is how you would model a blog with users, posts, and comments on each platform:

Supabase: PostgreSQL Schema

-- Supabase: Relational schema with SQL
CREATE TABLE users (
  id UUID DEFAULT gen_random_uuid() PRIMARY KEY,
  email TEXT UNIQUE NOT NULL,
  display_name TEXT,
  avatar_url TEXT,
  created_at TIMESTAMPTZ DEFAULT now()
);

CREATE TABLE posts (
  id UUID DEFAULT gen_random_uuid() PRIMARY KEY,
  author_id UUID REFERENCES users(id) ON DELETE CASCADE,
  title TEXT NOT NULL,
  content TEXT,
  published BOOLEAN DEFAULT false,
  created_at TIMESTAMPTZ DEFAULT now()
);

CREATE TABLE comments (
  id UUID DEFAULT gen_random_uuid() PRIMARY KEY,
  post_id UUID REFERENCES posts(id) ON DELETE CASCADE,
  author_id UUID REFERENCES users(id) ON DELETE CASCADE,
  body TEXT NOT NULL,
  created_at TIMESTAMPTZ DEFAULT now()
);

-- Complex query: Top 5 authors by comment count
SELECT u.display_name, COUNT(c.id) AS comment_count
FROM users u
JOIN posts p ON p.author_id = u.id
JOIN comments c ON c.post_id = p.id
WHERE p.published = true
GROUP BY u.id
ORDER BY comment_count DESC
LIMIT 5;

Firebase: Firestore Data Model

// Firebase: Document-based NoSQL structure
// Collection: users/{userId}
{
  "email": "alice@example.com",
  "displayName": "Alice",
  "avatarUrl": "https://...",
  "createdAt": "2026-01-15T10:30:00Z"
}

// Collection: posts/{postId}
{
  "authorId": "user_abc123",
  "authorName": "Alice",  // Denormalized!
  "title": "My First Post",
  "content": "Hello world...",
  "published": true,
  "commentCount": 42,     // Denormalized counter!
  "createdAt": "2026-01-20T14:00:00Z"
}

// Subcollection: posts/{postId}/comments/{commentId}
{
  "authorId": "user_xyz789",
  "authorName": "Bob",    // Denormalized!
  "body": "Great post!",
  "createdAt": "2026-01-20T15:30:00Z"
}

// Note: "Top 5 authors by comments" requires
// a Cloud Function to aggregate across collections

Query power comparison: PostgreSQL can execute complex queries that are impossible or extremely expensive in Firestore. Aggregations, JOINs across tables, subqueries, window functions, and recursive CTEs all work natively. In Firestore, you typically need to denormalize data (duplicate it across documents) and use Cloud Functions for anything beyond basic queries.

Feature Comparison Table

Authentication

Both platforms provide comprehensive authentication solutions. Supabase Auth (based on GoTrue) and Firebase Auth support email/password, social OAuth, phone OTP, and magic links. Firebase additionally supports anonymous auth and has deeper integration with Google Sign-In.

Supabase Auth

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

const supabase = createClient(SUPABASE_URL, SUPABASE_ANON_KEY);

// Email/password sign up
const { data, error } = await supabase.auth.signUp({
  email: 'user@example.com',
  password: 'secure-password-123',
});

// OAuth (Google, GitHub, Discord, etc.)
const { data, error } = await supabase.auth.signInWithOAuth({
  provider: 'google',
  options: { redirectTo: 'https://myapp.com/callback' },
});

// Phone OTP
const { data, error } = await supabase.auth.signInWithOtp({
  phone: '+1234567890',
});

// Get current user
const { data: { user } } = await supabase.auth.getUser();

// Listen to auth state changes
supabase.auth.onAuthStateChange((event, session) => {
  console.log(event, session);
});

Firebase Auth

import { getAuth, createUserWithEmailAndPassword,
  signInWithPopup, GoogleAuthProvider,
  RecaptchaVerifier, signInWithPhoneNumber,
  onAuthStateChanged } from 'firebase/auth';

const auth = getAuth();

// Email/password sign up
const userCredential = await createUserWithEmailAndPassword(
  auth, 'user@example.com', 'secure-password-123'
);

// OAuth (Google)
const provider = new GoogleAuthProvider();
const result = await signInWithPopup(auth, provider);

// Phone auth
const recaptcha = new RecaptchaVerifier(auth, 'recaptcha', {});
const confirmation = await signInWithPhoneNumber(
  auth, '+1234567890', recaptcha
);
await confirmation.confirm('123456'); // OTP code

// Listen to auth state changes
onAuthStateChanged(auth, (user) => {
  if (user) console.log('Signed in:', user.uid);
  else console.log('Signed out');
});

Firebase Auth has a slight edge in mobile development with pre-built UI components (FirebaseUI) for Android, iOS, and web. Supabase Auth is more developer-friendly for web apps and integrates directly with Row Level Security policies.

Storage Comparison

Both platforms offer file storage with CDN delivery. Supabase Storage is built on S3-compatible object storage with direct PostgreSQL integration — you can use RLS policies on storage buckets. Firebase Cloud Storage uses Google Cloud Storage under the hood.

Supabase Storage

// Upload a file
const { data, error } = await supabase.storage
  .from('avatars')
  .upload('user-123/profile.png', file, {
    cacheControl: '3600',
    upsert: true,
  });

// Get public URL
const { data: { publicUrl } } = supabase.storage
  .from('avatars')
  .getPublicUrl('user-123/profile.png');

// Generate signed URL (time-limited access)
const { data: { signedUrl } } = await supabase.storage
  .from('private-docs')
  .createSignedUrl('report.pdf', 3600);

// Image transformation on the fly
const { data: { publicUrl: thumb } } = supabase.storage
  .from('avatars')
  .getPublicUrl('user-123/profile.png', {
    transform: { width: 200, height: 200, resize: 'cover' },
  });

Firebase Cloud Storage

import { getStorage, ref, uploadBytes,
  getDownloadURL } from 'firebase/storage';

const storage = getStorage();

// Upload a file
const storageRef = ref(storage, 'avatars/user-123/profile.png');
const snapshot = await uploadBytes(storageRef, file, {
  contentType: 'image/png',
  customMetadata: { uploadedBy: 'user-123' },
});

// Get download URL
const downloadUrl = await getDownloadURL(storageRef);

// Upload with progress tracking
const uploadTask = uploadBytesResumable(storageRef, file);
uploadTask.on('state_changed',
  (snapshot) => {
    const progress = (snapshot.bytesTransferred /
      snapshot.totalBytes) * 100;
    console.log('Upload: ' + progress + '%');
  },
  (error) => console.error(error),
  () => getDownloadURL(uploadTask.snapshot.ref)
);

Realtime Capabilities

Realtime is where Firebase originally made its name. Firebase Realtime Database was designed from the ground up for live data synchronization. Firestore added real-time listeners later. Supabase Realtime, powered by Phoenix (Elixir), offers three modes: Postgres Changes (listen to database changes), Broadcast (pub/sub messaging), and Presence (track online users).

Supabase Realtime

// 1. Postgres Changes: Listen to database changes
const channel = supabase
  .channel('posts-changes')
  .on('postgres_changes',
    { event: '*', schema: 'public', table: 'posts' },
    (payload) => {
      console.log('Change:', payload.eventType, payload.new);
    }
  )
  .subscribe();

// 2. Broadcast: Pub/sub for ephemeral messages
const room = supabase.channel('room-1');
room.on('broadcast', { event: 'cursor' }, (payload) => {
  updateCursorPosition(payload.x, payload.y);
});
room.subscribe();
room.send({ type: 'broadcast', event: 'cursor',
  payload: { x: 100, y: 200 } });

// 3. Presence: Track online users
const presence = supabase.channel('online-users');
presence.on('presence', { event: 'sync' }, () => {
  const state = presence.presenceState();
  console.log('Online:', Object.keys(state).length);
});
presence.subscribe(async (status) => {
  if (status === 'SUBSCRIBED') {
    await presence.track({ user_id: 'abc', name: 'Alice' });
  }
});

Firebase Realtime Listeners

import { getFirestore, collection, query, where,
  onSnapshot, orderBy, limit } from 'firebase/firestore';

const db = getFirestore();

// Listen to a single document
const unsub = onSnapshot(doc(db, 'posts', 'post-1'),
  (doc) => {
    console.log('Current data:', doc.data());
  }
);

// Listen to a filtered query
const q = query(
  collection(db, 'posts'),
  where('published', '==', true),
  orderBy('createdAt', 'desc'),
  limit(20)
);

const unsubscribe = onSnapshot(q, (snapshot) => {
  snapshot.docChanges().forEach((change) => {
    if (change.type === 'added') {
      console.log('New post:', change.doc.data());
    }
    if (change.type === 'modified') {
      console.log('Updated:', change.doc.data());
    }
    if (change.type === 'removed') {
      console.log('Removed:', change.doc.id);
    }
  });
});

// Firebase also supports offline persistence
// Data is cached locally and synced when online
// enableIndexedDbPersistence(db); // Firestore
// enableNetwork(db) / disableNetwork(db)

Firebase's offline persistence gives it a significant advantage for mobile apps — data is cached locally and synced when the device comes back online. Supabase does not have built-in offline support.

Edge Functions vs Cloud Functions

Supabase Edge Functions run on Deno at the edge (low latency, globally distributed). Firebase Cloud Functions run on Node.js in a specific region. Edge Functions have faster cold starts (~50ms vs ~500ms-3s for Cloud Functions) but have a 150MB memory limit.

Supabase Edge Function (Deno)

// supabase/functions/send-welcome-email/index.ts
import { serve } from 'https://deno.land/std@0.177.0/http/server.ts';
import { createClient } from 'https://esm.sh/@supabase/supabase-js@2';

serve(async (req) => {
  const { email, name } = await req.json();

  // Access Supabase with service role key
  const supabase = createClient(
    Deno.env.get('SUPABASE_URL')!,
    Deno.env.get('SUPABASE_SERVICE_ROLE_KEY')!
  );

  // Send email via Resend
  const res = await fetch('https://api.resend.com/emails', {
    method: 'POST',
    headers: {
      'Authorization': 'Bearer ' + Deno.env.get('RESEND_API_KEY'),
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({
      from: 'hello@myapp.com',
      to: email,
      subject: 'Welcome, ' + name + '!',
      html: '<h1>Welcome to our app!</h1>',
    }),
  });

  return new Response(JSON.stringify({ sent: true }),
    { headers: { 'Content-Type': 'application/json' } });
});

// Deploy: supabase functions deploy send-welcome-email
// Cold start: ~50ms | Max memory: 150MB

Firebase Cloud Function (Node.js)

// functions/src/index.ts
import { onCall, HttpsError } from 'firebase-functions/v2/https';
import { onDocumentCreated } from
  'firebase-functions/v2/firestore';
import * as admin from 'firebase-admin';

admin.initializeApp();

// Callable function
export const sendWelcomeEmail = onCall(async (request) => {
  if (!request.auth) {
    throw new HttpsError('unauthenticated', 'Login required');
  }

  const { email, name } = request.data;
  // Send email with your preferred service
  await sendEmail(email, name);
  return { sent: true };
});

// Firestore trigger: runs when a new user doc is created
export const onUserCreated = onDocumentCreated(
  'users/{userId}',
  async (event) => {
    const userData = event.data?.data();
    await admin.messaging().send({
      topic: 'new-users',
      notification: {
        title: 'New user joined!',
        body: userData?.displayName + ' signed up',
      },
    });
  }
);

// Deploy: firebase deploy --only functions
// Cold start: ~500ms-3s | Max memory: 8GB

Pricing Comparison

Pricing is one of the biggest differentiators and often the deciding factor. Firebase charges per operation (reads, writes, deletes), which can lead to unpredictable costs. Supabase charges for compute resources and storage, making costs more predictable.

Here is a real cost comparison at different scales:

Free Tier Comparison

Estimated Cost: 10,000 Monthly Active Users

Estimated Cost: 100,000 MAU

Estimated Cost: 1,000,000 MAU

Key insight: Firebase costs can spike unpredictably due to read-heavy operations. A single Firestore listener on a frequently-updated document can consume millions of reads per month. Supabase pricing is more linear and predictable because it is based on compute and storage rather than operations.

Security Model: RLS vs Security Rules

Supabase uses PostgreSQL Row Level Security (RLS) — policies written in SQL that are enforced at the database level. Firebase uses Security Rules — a custom JSON-like DSL that is evaluated in a sandboxed environment outside the database.

Supabase Row Level Security

-- Enable RLS on the posts table
ALTER TABLE posts ENABLE ROW LEVEL SECURITY;

-- Anyone can read published posts
CREATE POLICY "Public posts are viewable"
  ON posts FOR SELECT
  USING (published = true);

-- Users can only insert their own posts
CREATE POLICY "Users can create own posts"
  ON posts FOR INSERT
  WITH CHECK (auth.uid() = author_id);

-- Users can only update/delete their own posts
CREATE POLICY "Users can update own posts"
  ON posts FOR UPDATE
  USING (auth.uid() = author_id);

CREATE POLICY "Users can delete own posts"
  ON posts FOR DELETE
  USING (auth.uid() = author_id);

-- Admin role can do everything
CREATE POLICY "Admins have full access"
  ON posts FOR ALL
  USING (EXISTS (
    SELECT 1 FROM user_roles
    WHERE user_id = auth.uid() AND role = 'admin'
  ));

Firebase Security Rules

// firestore.rules
rules_version = '2';
service cloud.firestore {
  match /databases/{database}/documents {

    // Posts collection
    match /posts/{postId} {
      // Anyone can read published posts
      allow read: if resource.data.published == true;

      // Authenticated users can create posts
      allow create: if request.auth != null
        && request.resource.data.authorId
           == request.auth.uid;

      // Only the author can update/delete
      allow update, delete: if request.auth != null
        && resource.data.authorId
           == request.auth.uid;

      // Comments subcollection
      match /comments/{commentId} {
        allow read: if true;
        allow create: if request.auth != null;
        allow update, delete:
          if request.auth.uid
             == resource.data.authorId;
      }
    }

    // Admin override using custom claims
    match /{document=**} {
      allow read, write:
        if request.auth.token.admin == true;
    }
  }
}

RLS advantages: policies are SQL (familiar), enforced at the database level (cannot be bypassed), composable with views and functions. Firebase Rules advantages: easier to learn initially, pattern matching for document paths, and validation built in.

TypeScript Support

Supabase has a major advantage here. The Supabase CLI can generate TypeScript types directly from your PostgreSQL schema with supabase gen types typescript. Every query returns properly typed results. Firebase requires manual type definitions or third-party tools like firebase-admin with Zod validation.

// Supabase: Auto-generated types
// Run: supabase gen types typescript --local > types/supabase.ts

import { createClient } from '@supabase/supabase-js';
import type { Database } from './types/supabase';

const supabase = createClient<Database>(URL, KEY);

// Fully typed! IDE knows the shape of every table
const { data: posts } = await supabase
  .from('posts')         // autocomplete table names
  .select('id, title, users(display_name)') // typed joins
  .eq('published', true); // typed filter values

// posts is typed as:
// { id: string; title: string;
//   users: { display_name: string } | null }[]

// ---- Firebase: Manual types ----
// You must define interfaces yourself
interface Post {
  authorId: string;
  title: string;
  content: string;
  published: boolean;
  createdAt: Timestamp;
}

// Type assertion required on every query
const snapshot = await getDocs(
  collection(db, 'posts') as CollectionReference<Post>
);
const posts = snapshot.docs.map(doc => doc.data());

Self-Hosting and Vendor Lock-In

Supabase can be fully self-hosted using Docker Compose. The entire stack — PostgreSQL, GoTrue, PostgREST, Realtime, Storage, Studio — is open source. This means zero vendor lock-in: your data is in a standard PostgreSQL database that can be migrated to any PostgreSQL host.

# Self-host Supabase with Docker Compose
git clone https://github.com/supabase/supabase
cd supabase/docker
cp .env.example .env
# Edit .env: POSTGRES_PASSWORD, JWT_SECRET, SITE_URL, SMTP

docker compose up -d

# Services: PostgreSQL (:5432), PostgREST (:3000),
# GoTrue Auth (:9999), Realtime (:4000), Storage (:5000),
# Studio (:3000), Kong API Gateway (:8000)

Firebase cannot be self-hosted. Your data lives in Google Cloud, and migrating away requires significant effort. Firestore data must be exported to JSON/CSV and transformed for a different database. Cloud Functions must be rewritten. Authentication providers must be reconfigured.

Framework Integration

Both platforms provide SDKs for major frameworks, but the developer experience differs:

Performance Benchmarks

Performance varies significantly based on query patterns, data size, and region configuration. Here are typical benchmarks for common operations:

When to Choose Supabase

Migration Guide: Firebase to Supabase

Migrating from Firebase to Supabase is a common path as projects grow and need SQL capabilities. Here is a high-level migration guide:

Production Best Practices

Supabase Production Tips

• Enable RLS on every table — even if you think it is unnecessary
• Use database migrations (Supabase CLI) instead of manual schema changes
• Set up connection pooling (PgBouncer) for serverless environments
• Monitor query performance with pg_stat_statements
• Use Edge Functions for webhook handlers and API routes
• Enable Point-in-Time Recovery for production databases
• Set up database backups and test restore procedures
• Use read replicas for read-heavy workloads

Firebase Production Tips

• Always set Security Rules before deploying — default open rules are a security risk
• Use composite indexes proactively for complex queries
• Monitor Firestore usage carefully to avoid bill spikes
• Use batched writes for bulk operations (max 500 per batch)
• Enable Firestore bundle generation for frequently-read data
• Use Cloud Functions 2nd gen for better performance and longer timeouts
• Implement offline persistence only when needed (it increases SDK size)
• Use Firebase App Check to prevent API abuse

Community and Ecosystem

Firebase has a larger and more mature ecosystem, with over 8 years of production use. Google Developer Groups, extensive documentation, and thousands of tutorials make it easy to find answers. Supabase has a rapidly growing community, excellent documentation, and an active Discord with over 30,000 members. Supabase's open-source nature means the community contributes extensions, tools, and self-hosting guides.

Frequently Asked Questions