Supabase vs Firebase
The choice usually comes down to whether your data has relationships, and whether you need a way out later.
The verdict
Choose Supabase when your data has relationships or you want the option to leave, and choose Firebase when you need a mobile app live this week and the data stays document-shaped.
Both are hosted backends with auth, storage and a client SDK. The difference that matters is underneath: Firebase stores documents, Supabase is Postgres with an API in front of it.
That single fact drives everything below, including the parts nobody warns you about until you are two years in.
Side by side
Every row is a decision you will make once and live with. The ones near the bottom are where teams get surprised.
| Dimension | Supabase | Firebase |
|---|---|---|
| Data model | Relational Postgres, with joins and constraints | Document store, denormalise for reads |
| Queries | Full SQL, plus views and functions | Path lookups and limited compound queries |
| Realtime | Postgres replication, table-level | Mature, built for it from the start |
| Auth | Built in, row-level security in the database | Built in, rules in a separate language |
| Offline support | Not built in | Strong, the main reason to pick it |
| Self-hosting | Supported, open source | Not possible |
| Exit path | A Postgres dump anyone can restore | Export exists, the shape is Firebase's |
| Offline sync | Not built in. You build it or you do without. | Mature. The main reason to pick it. |
| Row-level security | In the database, next to the data. | Rules in a separate language, evaluated per request. |
| Local development | Full stack runs in Docker offline. | Emulator suite, close but not identical to production. |
| Scaling limit you hit first | Postgres connection count. Solved with a pooler. | Query shape. Solved by denormalising, which is a rewrite. |
| Team that suits it | Anyone who already writes SQL. | Mobile teams who want to ship before choosing a backend. |
Which one fits your build?
Four questions about your situation, not your preferences. The answer updates as you go.
Will a report ever join users to orders to payments?
Does the app have to work with no signal?
Will anyone ask where the data is hosted?
What is the team strongest at?
Every outcome
- Supabase
- Your data has relationships and you want the option to leave. Postgres gives you both, and the setup cost is one afternoon.
- Firebase
- You need a mobile app live quickly and it has to work offline. Nothing else matches Firebase on either, and the document model will not bite you yet.
Supabase
Where it wins
- Postgres means joins, constraints and every tool that speaks SQL.
- Row-level security puts access rules next to the data, not in a separate rules file.
- Self-hosting is real, so a pricing change is not an emergency.
- Leaving is a database dump.
Where it hurts
- Realtime is newer than Firebase's and less forgiving at high fan-out.
- No first-class offline sync, which is a hard stop for some mobile apps.
- You are exposed to Postgres connection limits, so pooling becomes your problem sooner than you expect.
Firebase
Where it wins
- Fastest route from nothing to a working mobile app.
- Offline sync that genuinely works, which is rare.
- Realtime is battle-tested at very large scale.
- The surrounding Google tooling is mature.
Where it hurts
- Document modelling punishes relational data, and most business data is relational.
- Query limits push logic into the client, where it is harder to secure.
- No self-hosting, so there is no answer to a pricing change except paying it.
- Migrating away means rebuilding the data layer, not exporting it.
What we would pick, and why
| Criterion | Your situation | What we would build on |
|---|---|---|
| Internal tool, relational data | Reporting across users, orders and payments from week one. | Supabase. The joins you need do not exist in a document store. |
| Consumer mobile app | Field staff or customers using it away from signal. | Firebase. Offline sync is the feature you cannot rebuild cheaply. |
| Regulated client | A security review will ask where data lives. | Supabase, self-hosted. The answer is a location, not a vendor. |
| Two-week prototype | Proving an idea before anyone funds it. | Either. Pick the one your team already knows and move on. |
| Already on Firebase, hurting | Query limits pushing logic into the client. | Supabase, but budget a data-layer rewrite rather than a migration. |
Pick by the question you cannot answer later
Both will carry a prototype. The decision is about the shape of the thing in two years, and only one of these choices is reversible cheaply.
- 01If a report will ever join users to orders to payments, take Postgres.
- 02If the app must work on a train with no signal, take Firebase.
- 03If a compliance reviewer will ask where the data lives, take the one you can self-host.
- 04If the honest answer is that you do not know yet, take the one with the cheaper exit.
What we run, and why
We ship Supabase in four production systems. Shift Link handles workforce compliance for healthcare and logistics. Lexpair matches legal leads. Trading Copilot sends real-time forex alerts, and Extraaje runs employee engagement.
Three of the four needed relational reporting inside the first year. That pattern drives the verdict above, not a preference for the newer tool. The one place we felt the difference in the other direction was realtime fan-out, where Firebase would have been calmer.
Four systems we run on it
Common questions
01Can you use both?
Yes, and it is a reasonable pattern. Teams keep Firebase for push notifications and offline sync while running the relational core on Supabase. The cost is two auth systems, so pick one as the source of truth for identity and treat the other as a client.
02How hard is migrating from Firebase to Supabase?
Harder than the export step suggests. The data moves in an afternoon. The work is rebuilding the parts of your app that assumed document reads. Security rules also have to be rewritten as row-level policies. Budget for a rewrite of the data layer rather than a migration of it.
03Is Supabase production-ready?
Yes, with the connection-pooling caveat. It is Postgres, which is as proven as software gets, plus a hosted API layer that is younger. The failure mode we have hit is connection exhaustion under load. A pooler solves it. It is a known quantity, not a surprise.
04Which is cheaper?
Neither reliably, and the pricing pages change too often for a fair answer. The structural difference matters more: Supabase can be self-hosted, so a pricing change is a decision, while on Firebase it is a bill.
