Supabase vs Convex vs Firebase for Startups (2026)
You're building an MVP. You need a backend fast. Supabase, Convex, and Firebase are the three backends that let you ship in days, not weeks. But they're fundamentally different. Here's which one to pick for your startup.
Quick Verdict
- Supabase — Best all-around. SQL, auth, storage, real-time. Most versatile.
- Convex — Best for real-time apps. Reactive queries, end-to-end TypeScript, best DX.
- Firebase — Best for mobile. Offline-first, best SDKs for iOS/Android.
Speed to MVP
How fast can you go from zero to working product?
| Milestone | Supabase | Convex | Firebase |
|---|---|---|---|
| Auth working | 30 min | 30 min | 15 min |
| Database + CRUD | 1 hour | 30 min | 1 hour |
| Real-time features | 2 hours | 0 (built-in) | 30 min |
| File storage | 30 min | 15 min | 30 min |
| Full MVP | 1-2 days | 1 day | 1-2 days |
Convex is fastest because everything is integrated and reactive by default. Supabase requires more manual wiring. Firebase is fast for mobile.
Cost at Startup Scale
Startups are cost-sensitive. Here's what you'll actually pay:
Free Tiers
| Supabase | Convex | Firebase | |
|---|---|---|---|
| Database | 500MB | No limit (rows) | 1GB (Firestore) |
| Auth | 50K MAU | Via integration | Unlimited |
| Storage | 1GB | 1GB | 5GB |
| Functions | 500K invocations | 1M calls | 2M invocations |
| Bandwidth | 2GB | 1GB | 360MB/day |
At 1,000 Users
| Supabase | Convex | Firebase | |
|---|---|---|---|
| Estimated cost | $25/mo | $25/mo | $25-75/mo |
Firebase's per-read pricing makes it unpredictable. Supabase and Convex have predictable costs.
At 10,000 Users
| Supabase | Convex | Firebase | |
|---|---|---|---|
| Estimated cost | $25-50/mo | $25-75/mo | $100-500/mo |
Firebase gets expensive at scale. Supabase stays cheapest.
Data Model
Supabase (SQL/Relational)
-- Think in tables, joins, and foreign keys
SELECT users.name, orders.total
FROM users
JOIN orders ON users.id = orders.user_id
WHERE orders.status = 'completed'
Pros: Powerful queries, complex data models, familiar SQL. Cons: Schema migrations required, more upfront planning.
Convex (Document with Relations)
// Think in documents with references
const orders = await ctx.db
.query("orders")
.filter(q => q.eq(q.field("status"), "completed"))
.collect()
const results = await Promise.all(
orders.map(async (order) => ({
...order,
user: await ctx.db.get(order.userId),
}))
)
Pros: Flexible schema, easy iterations, TypeScript-native. Cons: No SQL, manual joins, less query power.
Firebase (NoSQL/Document)
// Think in document collections
const ordersRef = collection(db, "orders")
const q = query(ordersRef, where("status", "==", "completed"))
const snapshot = await getDocs(q)
Pros: Flexible, fast reads, great for simple data. Cons: No joins, denormalize everything, complex queries are painful.
Winner: Supabase for complex data. Convex for flexible iteration. Firebase for simple document storage.
Developer Experience
Supabase
- Dashboard with SQL editor
- Auto-generated REST API (PostgREST)
- TypeScript types from schema (supabase gen types)
- Row-level security for auth-based access
- Familiar if you know SQL/Postgres
Convex
- Write backend functions in TypeScript
- Reactive queries update UI automatically
- End-to-end type safety (no codegen)
- Best TypeScript DX of the three
- Newer paradigm — learning curve
Firebase
- Most mature SDKs (15+ platforms)
- Firebase Console for data management
- Security rules (custom language)
- Emulator suite for local dev
- Largest community, most tutorials
Winner: Convex for TypeScript developers. Firebase for mobile developers. Supabase for SQL developers.
Scaling Concerns
Supabase
Postgres scales well. Upgrade compute for more connections. Read replicas for heavy read loads. pgvector for AI features. Proven technology under the hood.
Convex
Serverless — scales automatically. No connection management. But you're dependent on Convex's infrastructure. No self-hosting option.
Firebase
Google-scale infrastructure. Handles millions of concurrent users. But costs scale linearly with reads/writes — can get very expensive.
Winner: Supabase for cost-effective scaling. Firebase for raw scale.
What About Auth?
| Supabase | Convex | Firebase | |
|---|---|---|---|
| Built-in auth | ✅ (GoTrue) | ❌ (use Clerk) | ✅ (Firebase Auth) |
| OAuth providers | 20+ | Via Clerk: 20+ | 15+ |
| Passwordless | ✅ | Via Clerk | ✅ |
| User management | ✅ Dashboard | Via Clerk | ✅ Dashboard |
Supabase and Firebase have built-in auth. Convex works with Clerk (which is excellent but adds $25/month at scale).
When to Use Each
Choose Supabase When
- Building a SaaS or web app
- You know SQL (or want to learn)
- Need complex queries and data relationships
- Want the most versatile backend
- Cost predictability matters
- Need pgvector for AI features
Choose Convex When
- Building collaborative/real-time features
- React/Next.js TypeScript stack
- Best DX is your priority
- Building chat, dashboards, or live apps
- Team values type safety above all
Choose Firebase When
- Building mobile-first (iOS/Android)
- Offline-first is critical
- Already in Google Cloud
- Need proven scale from day one
- Team knows Firebase
The Startup Decision Framework
-
What are you building?
- Web SaaS → Supabase
- Real-time collaborative app → Convex
- Mobile app → Firebase
-
What's your team's background?
- SQL/Postgres → Supabase
- TypeScript-first → Convex
- Mobile/Google → Firebase
-
What matters most?
- Cost control → Supabase
- Developer speed → Convex
- Scale confidence → Firebase
FAQ
Can I switch later?
Supabase → Firebase: painful (SQL → NoSQL). Convex → Supabase: painful (different paradigm). Choose carefully, but don't overthink it — all three can take you to $1M ARR.
Which is best for a solo founder?
Supabase or Convex. Both let you move fast with minimal ops. Firebase works but costs add up faster.
Do I need all these features for an MVP?
No. Start with auth + database + basic API. Add storage and real-time when you need them. All three let you start small.
Bottom Line
Supabase is the safest choice for most startups. SQL is versatile, pricing is predictable, and it handles everything from MVP to scale. Convex is the best DX for React developers building real-time features. Firebase is the go-to for mobile apps.
Pick one and start building. The backend is never the reason startups fail — not building fast enough is.