- Supabase, for almost any read-heavy application. - Firestore charges per document read; Supabase charges for compute. - Firebase wins for low-traffic, spiky apps where paying nothing at idle beats a flat instance fee.

Firebase vs Supabase

Q: Is Supabase a drop-in Firebase replacement?

- No. It covers the same surfaces: database, auth, storage, functions, realtime. - But the data model is relational, not document-based, so a port is a re-model. - The auth and storage APIs are close enough that those parts go quickly.

Q: Can Supabase do offline sync like Firestore?

- Not natively. - You add a local-first layer such as PowerSync or ElectricSQL, or build a cache and write queue yourself. - Firestore's offline persistence is one of its genuinely hard-to-replace features.

Q: Does Firebase support SQL now?

- Firebase Data Connect puts a managed Postgres behind a GraphQL layer. - So there's a relational option inside the Firebase console. - It's a different product from Firestore with a different pricing model. - Choosing it puts you head-to-head with Supabase, whose plain-Postgres access is simpler.

Q: Which is better for a team that doesn't know SQL?

- Firebase is a faster start; Supabase is a better investment. - SQL is the most transferable skill in this comparison. - Modern tooling and any decent LLM flatten the learning curve considerably.

Choose Supabase for relational data, SQL and portability; choose Firebase for mobile-first apps wanting Google's client SDKs, offline sync and the surrounding analytics and push ecosystem.

Editorial judgement last reviewed 23 July 2026

Should I use Firebase or Supabase for a new app?

Firebase is a whole mobile platform, not just a database.
Crashlytics, Analytics, Cloud Messaging, Remote Config, A/B testing and App Distribution are all wired in.
For an iOS and Android app, that bundle beats any single property of the datastore.
Supabase's advantage is that it is Postgres.
Real foreign keys, joins without denormalising, extensions, and a pg_dump exit rather than a rewrite.
The deciding question is usually your data shape, not your framework.
Firestore charges per document read, pushing you toward denormalisation synced by Cloud Functions.
Reasonable for feeds, chat and profiles; painful for many-to-many, reporting or finance-shaped correctness.
For most new web products, choose Supabase: relational data and a team that knows SQL.
For mobile-first products where offline is first-class, Firebase's client SDKs remain the best.
Supabase has nothing matching Firestore's offline persistence out of the box.
Second-order consideration: Firebase is Google, excellent infrastructure but a deprecation track record.
Supabase is open source, self-hostable and much younger.

Which one should you pick?

Choose Firebase if…

You're shipping native iOS and Android and want SDKs with a decade of polish.
Offline-first is a requirement: Firestore's local persistence and conflict handling are the best default here.
You want push, crash reporting and analytics from the same console as your database.
Your data is genuinely document-shaped: profiles, feeds, chat threads, read far more than joined.
You're comfortable with Google Cloud billing and watching read counts, the meter that runs.

Choose Supabase if…

Your data is relational: if you're sketching join tables, pick Postgres.
You want to write SQL, or want Drizzle, Prisma or Kysely to work normally.
You need reporting, analytics or admin queries over production data without exporting first.
You want a credible exit: Postgres is the most portable data store here.
You want row-level security enforced by the database, and you'll write and test the policies.
Your product is web-first, or web plus a React Native app without deep offline sync.

Data model: documents versus tables, and why it decides the project

Firestore is a hierarchical document store: collections, subcollections, shallow queries, no joins.
You model by duplicating: a message stores the sender's name and avatar to avoid extra reads.
Change an avatar and a Cloud Function rewrites every message, or you accept stale data.
A legitimate architecture, but hard to reverse, and more expensive the longer the project runs.
Postgres does the opposite: you normalise, join, and the database enforces referential integrity.
A new access pattern is a new query, not a new collection plus backfill plus sync function.
The cost: thinking about indexes and pooling, and a weaker realtime layer than Firestore's.
Heuristic: write down your five most-run queries.
If none need more than one collection, Firestore is comfortable.
If three are joins, you'll fight Firestore for the life of the project.

Pricing: per-read versus per-instance

Firebase bills Firestore per document read, write and delete, plus storage and egress.
This is its single most important operational fact.
A list of 50 items costs 50 reads every load, per user.
Add a realtime listener and every change to those documents costs another read.
Teams are surprised by a UI that re-reads a collection on every navigation.
Mitigations exist, caching, bundle loading, denormalised counters, listener scoping, but they're pure billing-model work.
Supabase bills like a server: flat project fee, compute by instance, then storage and bandwidth.
A query returning 50 rows costs the same as one returning 1.
Run a bad query a million times and your bill won't move; your CPU graph will.
Neither model is inherently cheaper.
Firebase wins for spiky, low-traffic apps that would otherwise pay for idle compute.
Supabase is dramatically cheaper for read-heavy apps and far easier to forecast.

Realtime and offline

Firestore listeners are the mature product here.
They work offline, queue local writes, replay on reconnect and resolve conflicts last-write-wins.
The client SDK keeps a local cache that survives app restarts.
For a mobile app used on a train, that's not a nice-to-have.
Supabase Realtime streams Postgres logical replication over a websocket.
You subscribe to table changes with optional filters and receive row-level events.
Fast and simple, but not offline sync: no local persistence, write queue or conflict resolution.
Teams needing offline reach for ElectricSQL, PowerSync or a hand-rolled cache, meaningful extra work.
If offline-first is a requirement, this section alone probably decides it.
If your app assumes connectivity, both are adequate; decide on the data model instead.

Lock-in, longevity and the ecosystem around each

Supabase is open source under a permissive licence and can be self-hosted.
Most teams never will, but the option changes the negotiation if pricing moves against you.
The Postgres underneath moves to any provider.
Firebase cannot be self-hosted, and Firestore's query semantics exist nowhere else.
Migrating off means exporting JSON and rebuilding against something relational.
Same class of work as leaving Convex, usually larger because Firebase projects are older.
Firebase's surrounding platform has no Supabase equivalent.
Cloud Messaging, Crashlytics, Remote Config, App Check.
On Supabase you assemble those from other vendors: more choice, more invoices.
Longevity cuts both ways: Google deprecates products; Supabase is a venture-funded startup.
The open-source escape hatch mitigates, but doesn't eliminate, the startup risk.

Frequently asked questions

Is Supabase a drop-in Firebase replacement?

No. It covers the same surfaces: database, auth, storage, functions, realtime.
But the data model is relational, not document-based, so a port is a re-model.
The auth and storage APIs are close enough that those parts go quickly.

Which is cheaper?

Supabase, for almost any read-heavy application.
Firestore charges per document read; Supabase charges for compute.
Firebase wins for low-traffic, spiky apps where paying nothing at idle beats a flat instance fee.

Can Supabase do offline sync like Firestore?

Not natively.
You add a local-first layer such as PowerSync or ElectricSQL, or build a cache and write queue yourself.
Firestore's offline persistence is one of its genuinely hard-to-replace features.

Does Firebase support SQL now?

Firebase Data Connect puts a managed Postgres behind a GraphQL layer.
So there's a relational option inside the Firebase console.
It's a different product from Firestore with a different pricing model.
Choosing it puts you head-to-head with Supabase, whose plain-Postgres access is simpler.

Which is better for a team that doesn't know SQL?

Firebase is a faster start; Supabase is a better investment.
SQL is the most transferable skill in this comparison.
Modern tooling and any decent LLM flatten the learning curve considerably.

All convex alternatives, compared field by field

Convex vs SupabaseShould I build on Convex or Supabase?