Supabase vs Firebase: which backend should you choose?

Tables versus documents

Supabase is PostgreSQL underneath. Your data lives in tables that reference each other, and you can ask almost any question of it in SQL. “Which customers ordered more than three times last quarter, and from which region?” is one query.

Firebase’s main database, Firestore, stores documents in collections. It’s quick and pleasant for apps where each screen reads one self-contained thing, like a chat thread or a user profile, and its real-time updates are excellent. Questions that combine different kinds of data are harder, and teams often end up copying the same data into several documents to keep reads fast. Firebase has added a PostgreSQL option called Data Connect, but most Firebase apps we see still run on Firestore.

Security works the same way in both

In both platforms, the app talks to the database directly from the browser or phone, so security rules are what stand between your users’ data and everyone else. Supabase uses PostgreSQL row-level security policies; Firebase has its own rules language. The most common pre-launch problem we find is the same in both: rules that are missing or far too loose. Whichever you pick, sign in as two different test users and check what each can see.

Reporting and AI tip it for most businesses

This is usually the deciding factor. Because Supabase is PostgreSQL, reporting tools like Data Studio or Retool can connect straight to it, and you can add AI search over your own data with pgvector in the same database. With Firestore, reporting generally means exporting data somewhere else first, and that export becomes one more thing to maintain.

Cost behaves differently

Firebase charges largely by document reads, writes and storage, so a busy screen that reads hundreds of documents can surprise you on the bill. Supabase pricing leans more on database size, compute and usage limits, which most teams find easier to predict. Prices change, so run both pricing pages against your real usage, and set budget alerts whichever you choose.

Think about leaving before you arrive

Supabase is open source and plain PostgreSQL underneath, so you can move your data to any PostgreSQL host if you ever need to. Leaving Firebase means reshaping documents into a different structure, which is a real project. If you’re unsure where the product is going, that alone often settles it.

When we’d still pick Firebase

For a mobile-first app where most screens read simple, self-contained data, especially one that already leans on other Firebase services like Crashlytics, Analytics or Cloud Messaging, Firebase is a solid choice. Same if your team already knows Firestore well and doesn’t need much reporting. It suits a narrower set of products than PostgreSQL, but it suits them well.

Moving from Firebase to Supabase

It’s a common move once an app grows up and needs reporting or more complex queries. It involves designing proper tables from your documents, migrating users and files, and rewriting the app’s data access. We run it like any other database migration: a dry run first, record counts before and after, and a switchover with a tested way back.