Quick verdict
Pick Supabase for SQL-shaped data, multi-tenant apps with row-level security, and the simplest Expo integration. Pick Firebase for document/realtime-tree data, generous free auth at scale, and when your team already lives in Google Cloud.
Head-to-head comparison
| Dimension | Supabase | Firebase |
|---|---|---|
| Database | Postgres (SQL) | Firestore (doc) / RTDB (tree) |
| Query shape | Full SQL + joins | Document / path-based |
| Row-level security | Built in, expressive | Security rules (less expressive) |
| Auth | Email, OAuth, passkeys | Email, OAuth, phone |
| Expo integration | Managed workflow, works in Expo Go | Config plugin + dev build required |
| Realtime | Postgres changes over WebSocket | Native realtime (most mature) |
| Free tier | 500MB DB, 50k MAU, 1GB storage | 50k MAU, generous reads |
| Open source / self-host | Yes | No |
| Lock-in risk | Low (standard Postgres) | Medium (proprietary DB) |
What each actually is
Supabase is an open-source backend-as-a-service built on Postgres: auth, SQL database with row-level security (RLS), object storage, realtime over websockets, and edge functions. You can self-host the entire stack if compliance ever demands it.
Firebaseis Google’s managed backend: Auth, Firestore (document database), Realtime Database (JSON tree), Cloud Functions, and Cloud Storage. Battle-tested for over a decade and deeply integrated with Google Cloud, Analytics, and Cloud Messaging.
Expo setup, side by side
This is where the gap is widest for React Native developers. Supabase:
npx expo install @supabase/supabase-js @react-native-async-storage/async-storage
import { createClient } from '@supabase/supabase-js'
export const supabase = createClient(SUPABASE_URL, SUPABASE_ANON_KEY, {
auth: { storage: AsyncStorage, persistSession: true },
})That’s the whole integration. It runs in Expo Go, in development builds, everywhere.
Firebase needs @react-native-firebase/app plus its config plugin, google-services.json / GoogleService-Info.plist, and — critically — it will not run in Expo Go. You need a development build before you see your first query succeed. Auth-only setups can limp along on the JS SDK, but most production apps end up on React Native Firebase and eat the native-build workflow.
If you’re prototyping fast or new to mobile, that difference alone decides it.
Where Supabase wins
- SQL-shaped data. Users, posts, follows, comments — relational data wants joins, not nested document paths. Firestore makes you denormalize and maintain copies; Postgres just joins.
- Multi-tenant apps. RLS makes workspace-scoped queries trivial and safe: one policy, enforced at the database layer, instead of security rules you have to mirror in every query. See How to Build a SaaS Mobile App with AI.
- Pricing predictability. Flat $25/mo Pro tier with usage add-ons. No read-multiplication surprises.
- Portability. It’s standard Postgres.
pg_dumpand leave whenever you want.
Where Firebase wins
- Realtime maturity. For flat, chat-style data streams, Realtime Database is still the gold standard — a decade of production hardening at massive scale.
- Free auth at scale. 50k MAUs free with generous read quotas suits consumer apps with light data needs.
- The Google ecosystem. Analytics, Remote Config, Cloud Messaging, Crashlytics, App Check — one dashboard.
- Document-shaped data. Chat messages, journal entries, event logs — if your data is naturally documents, Firestore is elegant.
Real pricing at three stages
| Stage | Supabase | Firebase |
|---|---|---|
| MVP (0–1k users) | Free | Free |
| 10k MAU, moderate reads | $25/mo Pro | ~$0–50/mo (read-dependent) |
| 100k MAU, read-heavy | $25 base + predictable add-ons | Highly variable — unoptimized Firestore queries can hit hundreds/mo |
The pattern: Firebase is cheaper for auth-heavy apps with few reads. Supabase is cheaper and — more importantly — predictablefor read-heavy apps. The infamous “surprise Firestore bill” almost always traces to a list screen re-reading whole collections; SQL’s select with a limitdoesn’t have that failure mode.
What changed in 2026
- Supabase passkey auth left beta — passwordless sign-in with no extra vendor.
- Firestore added limited SQL-ish aggregation queries, narrowing (not closing) the joins gap.
- Expo SDK’s managed workflow keeps widening Supabase’s setup advantage: config-plugin friction stayed;
supabase-jsfriction didn’t.
Decision framework
Choose Supabaseif any of these are true: your data model has relationships (most apps), you’re multi-tenant, you want Expo Go development, you might self-host, or you want to reason about cost in advance.
Choose Firebase if: your app is chat/feed-shaped documents, you need Google ecosystem tooling (especially Analytics + Messaging in one place), or auth volume is your main cost driver.
Still unsure? Default Supabase. Migration off Postgres is a weekend; migration off Firestore is a rewrite.
Don’t want to wire a backend at all? ShipNative generates React Native apps with auth and a database already connected — describe your app, press Go Live when you’re ready. Start free at shipnative.dev.