Why Developers Are Switching from Firebase to Supabase (And You Should Too)

Something shifted in the developer world.

Firebase used to be the default answer to "what backend should I use?" For years, it was the obvious choice — fast setup, real-time database, free tier, backed by Google. Done.

But scroll through any developer community in 2026 — Reddit, X, Discord, Hacker News — and you will see the same pattern: developers are leaving Firebase for Supabase. Not just a few. Thousands.

This is not hype. There are real, practical reasons driving this migration. And if you are still on Firebase, this article will show you exactly why the switch is happening — and how to do it yourself.

The 4 Reasons Developers Are Leaving Firebase

1. The Pricing Time Bomb

This is the number one reason. Every Firebase developer has a horror story.

Firebase charges per document read and write. Sounds fine until your app gets traffic:

Small app (1,000 users):
├── 500K Firestore reads/month  → $0.30
├── 100K Firestore writes/month → $0.18
└── Total: ~$0.50/month         → Feels free!

Growing app (50,000 users):
├── 50M Firestore reads/month   → $30
├── 10M Firestore writes/month  → $18
├── Cloud Functions              → $15
└── Total: ~$63/month           → Getting expensive

Popular app (500,000 users):
├── 500M Firestore reads/month  → $300
├── 100M Firestore writes/month → $180
├── Cloud Functions              → $80
├── Bandwidth                    → $50
└── Total: ~$610/month          → WHERE DID THIS COME FROM?

The problem is not just the cost — it's the unpredictability. A single viral moment, a bot scraping your app, or a poorly optimized query can spike your bill overnight.

Real story: A developer shipped a dashboard that fetched 100 Firestore documents on page load. With 10,000 daily active users, that is 1 million reads per day — 30 million per month — just from one page. The monthly bill jumped from $15 to $180 overnight.

Supabase pricing is flat. $25/month for Pro. Your app can make a billion queries — the price stays the same. You pay for compute and storage, not for how many times your users press a button.

2. NoSQL Hit a Wall

Firestore seemed great when your app was simple. But then you needed to:

Show a leaderboard → No ORDER BY with LIMIT across collections
Count total users → No COUNT — you read every document or maintain a counter
Join user data with orders → No JOINs — you denormalize or make multiple queries
Search by multiple fields → Requires composite indexes for every combination
Run analytics → Read every document, aggregate client-side

Here is what a simple "top customers" query looks like in both:

Supabase (PostgreSQL):

SELECT
  users.name,
  COUNT(orders.id) as order_count,
  SUM(orders.total) as total_spent
FROM users
JOIN orders ON users.id = orders.user_id
WHERE orders.created_at > NOW() - INTERVAL '30 days'
GROUP BY users.id
ORDER BY total_spent DESC
LIMIT 10;

One query. One database call. Instant.

Firebase (Firestore):

// Step 1: Get all orders from last 30 days
const ordersSnap = await getDocs(
  query(
    collection(db, 'orders'),
    where('createdAt', '>', thirtyDaysAgo)
  )
);

// Step 2: Group by userId (client-side)
const userTotals = {};
ordersSnap.forEach(doc => {
  const order = doc.data();
  if (!userTotals[order.userId]) {
    userTotals[order.userId] = { count: 0, total: 0 };
  }
  userTotals[order.userId].count++;
  userTotals[order.userId].total += order.total;
});

// Step 3: Sort client-side
const topCustomers = Object.entries(userTotals)
  .sort(([, a], [, b]) => b.total - a.total)
  .slice(0, 10);

// Step 4: Fetch each user's name (N more reads!)
const results = await Promise.all(
  topCustomers.map(async ([userId, stats]) => {
    const userDoc = await getDoc(doc(db, 'users', userId));
    return { name: userDoc.data().name, ...stats };
  })
);

That is potentially thousands of document reads for something PostgreSQL does in one query. And you are paying for every single read.

3. Vendor Lock-In Is Real

With Firebase:

Your data is in Firestore (proprietary NoSQL format)
Your auth is in Firebase Auth (Google-only)
Your functions are Cloud Functions (Google Cloud)
You cannot self-host any of it
Exporting data means manually converting documents to another format

If Google changes pricing, deprecates a feature, or you just want to move — you are rewriting your entire backend.

With Supabase:

Your data is in PostgreSQL — the industry standard
Export with pg_dump, import anywhere
Fully open-source — self-host with Docker
Zero proprietary formats

# Leave Supabase? Take your data with you.
pg_dump -h db.yourproject.supabase.co -U postgres -d postgres > backup.sql

# Restore to any PostgreSQL host
psql -h your-new-host.com -U postgres -d myapp < backup.sql

Supabase is the only major BaaS that is fully open-source. If Supabase disappeared tomorrow, you could self-host everything with Docker and keep building. Try doing that with Firebase.

4. Server-Side Rendering Changed Everything

Firebase was built for a world of client-side SPAs — single-page applications where JavaScript runs in the browser.

But the web moved on. Next.js App Router, Server Components, Server Actions — the future is server-first. And Firebase does not fit.

The Firebase problem with Next.js:

// You need TWO different Firebase SDKs
import { getFirestore } from 'firebase/firestore'        // Client
import { getFirestore } from 'firebase-admin/firestore'  // Server

// Different APIs, different auth contexts, different behavior
// Client SDK uses user tokens, Admin SDK bypasses security rules
// You constantly context-switch between two mental models

Supabase with Next.js:

// One API, works everywhere
import { createClient } from '@/lib/supabase/server'

// Server Component
export default async function Page() {
  const supabase = await createClient()
  const { data } = await supabase.from('posts').select('*')
  return <PostList posts={data} />
}

// Server Action
export async function createPost(formData: FormData) {
  const supabase = await createClient()
  await supabase.from('posts').insert({ title: formData.get('title') })
  revalidatePath('/posts')
}

Same client, same API, same mental model. Supabase's @supabase/ssr package was built for the server-first world.

How to Migrate: Step-by-Step

Ready to switch? Here is the practical migration path.

Step 1: Map Your Firestore Collections to PostgreSQL Tables

Firestore documents become rows. Collections become tables. Nested data gets normalized.

Before (Firestore):

users/
  userId1/
    name: "Alice"
    email: "alice@example.com"
    orders/
      orderId1/
        product: "Widget"
        amount: 29.99
        status: "shipped"

After (PostgreSQL):

CREATE TABLE users (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  name TEXT NOT NULL,
  email TEXT UNIQUE NOT NULL,
  created_at TIMESTAMPTZ DEFAULT NOW()
);

CREATE TABLE orders (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  user_id UUID REFERENCES users(id) ON DELETE CASCADE,
  product TEXT NOT NULL,
  amount DECIMAL(10,2) NOT NULL,
  status TEXT DEFAULT 'pending',
  created_at TIMESTAMPTZ DEFAULT NOW()
);

-- Enable RLS
ALTER TABLE users ENABLE ROW LEVEL SECURITY;
ALTER TABLE orders ENABLE ROW LEVEL SECURITY;

CREATE POLICY "Users see own data" ON users
  FOR SELECT USING (auth.uid() = id);

CREATE POLICY "Users see own orders" ON orders
  FOR SELECT USING (auth.uid() = user_id);

Step 2: Migrate Auth Users

Export from Firebase, import to Supabase:

// scripts/migrate-auth.ts
import admin from 'firebase-admin'
import { createClient } from '@supabase/supabase-js'

const firebase = admin.initializeApp({
  credential: admin.credential.cert('./firebase-service-account.json')
})

const supabase = createClient(
  process.env.SUPABASE_URL!,
  process.env.SUPABASE_SERVICE_ROLE_KEY!
)

async function migrateUsers() {
  const listResult = await firebase.auth().listUsers(1000)

  for (const user of listResult.users) {
    const { data, error } = await supabase.auth.admin.createUser({
      email: user.email!,
      email_confirm: true,
      user_metadata: {
        name: user.displayName,
        avatar_url: user.photoURL,
        firebase_uid: user.uid // keep reference
      }
    })

    if (error) {
      console.error(`Failed to migrate ${user.email}:`, error.message)
    } else {
      console.log(`Migrated: ${user.email} → ${data.user.id}`)
    }
  }
}

migrateUsers()

Send your users an email before migration: "We are upgrading our infrastructure. You may need to reset your password on your next login." This covers the password hash issue gracefully.

Step 3: Migrate Data

Export Firestore collections to PostgreSQL:

// scripts/migrate-data.ts
import admin from 'firebase-admin'
import { createClient } from '@supabase/supabase-js'

const db = admin.firestore()
const supabase = createClient(
  process.env.SUPABASE_URL!,
  process.env.SUPABASE_SERVICE_ROLE_KEY!
)

async function migrateCollection(
  collectionName: string,
  tableName: string,
  transform: (doc: any) => any
) {
  const snapshot = await db.collection(collectionName).get()
  const rows = snapshot.docs.map(doc => transform({
    firebase_id: doc.id,
    ...doc.data()
  }))

  // Insert in batches of 500
  for (let i = 0; i < rows.length; i += 500) {
    const batch = rows.slice(i, i + 500)
    const { error } = await supabase.from(tableName).insert(batch)

    if (error) {
      console.error(`Batch ${i} failed:`, error.message)
    } else {
      console.log(`Migrated ${Math.min(i + 500, rows.length)}/${rows.length} ${collectionName}`)
    }
  }
}

// Migrate users first (referenced by other tables)
await migrateCollection('users', 'users', (doc) => ({
  id: doc.firebase_id, // or map to new Supabase auth user ID
  name: doc.name,
  email: doc.email,
  created_at: doc.createdAt?.toDate() || new Date()
}))

// Then migrate orders
await migrateCollection('orders', 'orders', (doc) => ({
  user_id: doc.userId, // map to new user ID
  product: doc.product,
  amount: doc.amount,
  status: doc.status,
  created_at: doc.createdAt?.toDate() || new Date()
}))

Step 4: Update Your App Code

Replace Firebase SDK calls with Supabase equivalents:

// BEFORE: Firebase
import { collection, getDocs, addDoc, query, where } from 'firebase/firestore'

const q = query(collection(db, 'tasks'), where('userId', '==', user.uid))
const snapshot = await getDocs(q)
const tasks = snapshot.docs.map(doc => ({ id: doc.id, ...doc.data() }))

await addDoc(collection(db, 'tasks'), {
  title: 'New task',
  userId: user.uid,
  completed: false
})

// AFTER: Supabase
import { createClient } from '@/lib/supabase/server'

const supabase = await createClient()

// RLS handles the user filtering automatically
const { data: tasks } = await supabase
  .from('tasks')
  .select('*')
  .order('created_at', { ascending: false })

await supabase.from('tasks').insert({
  title: 'New task',
  // user_id is set automatically via RLS + auth.uid()
})

Notice how the Supabase version is shorter? You do not need to filter by user ID — Row Level Security handles it automatically. Less code, fewer bugs.

Step 5: Replace Firebase Services

Firebase Service	Supabase Equivalent
Firestore	PostgreSQL database
Firebase Auth	Supabase Auth
Cloud Storage	Supabase Storage
Cloud Functions	Supabase Edge Functions + Next.js Server Actions
Hosting	Vercel (for Next.js)
Realtime Database	Supabase Realtime
Analytics	PostHog or Plausible
Crashlytics	Sentry
Cloud Messaging	OneSignal or Novu

Migration Timeline

For a typical mid-size app:

Week 1:
├── Day 1-2: Set up Supabase project, design PostgreSQL schema
├── Day 3-4: Migrate auth users
└── Day 5: Migrate data

Week 2:
├── Day 1-3: Update app code (replace Firebase SDK with Supabase)
├── Day 4: Test everything
└── Day 5: Deploy + monitor

You do not have to migrate everything at once. Start with new features on Supabase. Migrate existing features one at a time. Run both in parallel until you are confident.

The Results After Switching

Developers who migrated report:

60-80% lower monthly costs — flat pricing vs per-read billing
Faster development — SQL queries replace complex NoSQL workarounds
Better Next.js integration — first-party SSR support, Server Actions
Simpler codebase — one API everywhere, RLS handles authorization
Peace of mind — open source, no vendor lock-in, data portability

Should You Switch?

Switch now if:

Your Firebase bill is growing faster than your revenue
You are fighting Firestore's query limitations
You are building with Next.js (App Router)
You want data ownership and portability
You are starting a new project

Stay on Firebase if:

Your app is deeply integrated with Google Cloud services
You rely heavily on Firebase Cloud Messaging for push notifications
Your team has deep Firebase expertise and no SQL experience
Your app is small, stable, and Firebase costs are negligible

For everyone else — especially if you are building with Next.js — the switch to Supabase is one of the best decisions you will make in 2026.

Ready to start building? Check out our step-by-step tutorial to build a full-stack app with Next.js and Supabase — you will have a working app in 20 minutes.

Related:

Originally published at https://www.iloveblogs.blog

Why Developers Are Switching from Firebase to Supabase (And You Should Too)

Why Developers Are Switching from Firebase to Supabase (And You Should Too)

The 4 Reasons Developers Are Leaving Firebase

1. The Pricing Time Bomb

2. NoSQL Hit a Wall

3. Vendor Lock-In Is Real

4. Server-Side Rendering Changed Everything

How to Migrate: Step-by-Step

Step 1: Map Your Firestore Collections to PostgreSQL Tables

Step 2: Migrate Auth Users

Step 3: Migrate Data

Step 4: Update Your App Code

Step 5: Replace Firebase Services

Migration Timeline

The Results After Switching

Should You Switch?

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