Supabase vs Firebase for startups

Reviewed 2026-09-30

Short answer: Supabase for most startup backends; Firebase for offline-first mobile apps or teams already committed to Google Cloud.

Both give a small team a database, auth, storage, and functions without running servers. They differ in the data model, Postgres tables against Firestore documents, and in what you pay for: Supabase bills for capacity, Firebase for operations.

Verdict

Supabase, for most startup backends. It is standard Postgres, its Pro plan bills for capacity with a spend cap on by default, and the database leaves with a pg_dump. It holds the Backend Infrastructure slot in our Founder Stack. Pick Firebase for an offline-first mobile app, or if your company already runs on Google Cloud.

Supabase holds the Backend Infrastructure slot in the Founder Stack

Supabase vs Firebase: side by side

Supabase vs Firebase, compared
Criterion	Supabase	Firebase
Database	Postgres	Cloud Firestore (document database) or Realtime Database
Free plan	2 projects; 500 MB database; 50,000 MAU; 1 GB storage; 5 GB egress; paused after 1 week of inactivity	Spark: Firestore 1 GiB stored, 50,000 reads, 20,000 writes, and 20,000 deletes a day, 10 GiB egress a month; Authentication 50,000 MAU
Entry paid plan	Pro from $25/month, including $10 of compute credits (one Micro instance); spend cap on by default	Blaze: no base fee listed; pay per use beyond the free quotas
Usage pricing	Pro includes 8 GB disk per project, 100,000 MAU, 100 GB storage, 250 GB egress; then $0.125/GB disk, $0.00325/MAU, $0.0213/GB storage, $0.09/GB egress	Firestore in Iowa (us-central1): $0.03 per 100,000 reads, $0.09 per 100,000 writes, $0.01 per 100,000 deletes; varies by location
Queries	No per-query charge listed	Each query costs at least one document read, even with no results; listeners are charged per document added or updated
Export	Standard Postgres: pg_dump and restore	Managed export to a Cloud Storage bucket; requires Blaze
Self-hosting	Supported, with Docker	—
Offline	—	Persistence on by default on Android and Apple; opt-in on web

Postgres or a document database

Supabase gives each project a Postgres database: tables, foreign keys, transactions, and SQL, usable from any Postgres client or ORM. Firestore stores documents in collections, and related data is often copied across documents to serve each screen's reads.

Most startup products are relational underneath: accounts, teams, roles, billing. In Postgres, changing that model is a schema migration; in a document store, it usually means a backfill job across existing documents.

How each bills

Supabase bills for capacity, Firebase for operations. Supabase Pro starts at $25 a month with $10 of compute credits, enough for one Micro instance, and its spend cap is on by default. Firestore on the Blaze plan has no listed base fee; beyond the free daily quotas it charges per document read, write, and delete: $0.03, $0.09, and $0.01 per 100,000 in Iowa (us-central1).

Per-operation billing makes read-heavy bugs expensive: every query costs at least one read, even when it returns nothing, and listeners are charged for each document added or updated in their results.

Leaving later

A Supabase database is standard Postgres, so pg_dump and restore move it to any Postgres host, and Supabase itself can be self-hosted with Docker. Auth, storage, and functions still need their own migration plan.

Firestore's managed export writes to a Cloud Storage bucket and requires the Blaze plan. Moving to a relational database also means remodelling the data and rewriting the queries built on the Firebase SDK.

When Firebase is the better choice

Supabase holds our backend slot. Pick Firebase when:

You're building a mobile app that must work offline: Firestore persistence is on by default on Android and Apple.
Your company already runs on Google Cloud and wants one bill and one console.
Your data really is document-shaped, with few relations between records.
Your usage fits inside the free daily quotas and you want no monthly fee.

Facts are checked against each vendor's own pages, listed below; the verdict is our opinion. Prices change, so confirm on the vendor's site. See disclosures.