Hosting and deploy

Supabase vs Firebase: which should you use?

Supabase and Firebase compared on database model, queries, security rules, auth, pricing and lock-in, and which fits an AI-built web app or a mobile app.

Supabase is built on PostgreSQL, a relational SQL database, and is open source. Firebase, from Google, is built around Firestore, a NoSQL document database, with deep mobile and Google Cloud integration. Choose Supabase for relational data, SQL and portability. Choose Firebase for mobile-first apps, offline sync and the Google ecosystem. Both need security rules written before launch.

Published 9 November 2026 · Last updated 9 November 2026

By Michal Měřínský. Audit methodology.

The core difference

Supabase: PostgreSQL tables with relations, joins and SQL. Access control with row level security policies in the database.
Firebase: Firestore stores documents in collections, optimized for reads by path. Access control with Firebase Security Rules. Firebase also offers SQL Connect, formerly Data Connect, which adds a PostgreSQL option through Cloud SQL.

Side by side

Data model: Supabase is relational. Firestore is document-based, which is flexible but makes joins and reporting harder.
Queries: Supabase supports full SQL. Firestore queries are limited by design and need indexes for compound queries.
Auth: both offer email, OAuth providers, phone and MFA.
Realtime and offline: both offer realtime updates. Firebase's offline sync for mobile is more mature.
Functions: Supabase Edge Functions in TypeScript. Cloud Functions for Firebase in Node.js or Python.
Pricing: Supabase charges a plan fee plus usage. Firestore charges per read, write and delete, which can grow quickly with chatty frontends.
Lock-in: Supabase is open source and Postgres can be moved anywhere. Firestore data and rules are specific to Google.

Which fits which project

AI-built web app with users, projects and teams: Supabase. Relational data and SQL fit, and builders such as Lovable and Bolt integrate it by default.
Mobile app with offline use and push notifications: Firebase, with its mature mobile SDKs and Google services.
Analytics, reporting or complex queries: Supabase, or Firebase with SQL Connect.
Already on Google Cloud: Firebase fits naturally.

Security on both

Both expose the database to the client through a public configuration, and both are secure only if rules are written. An open Firestore rule set can expose data; a Supabase table in an exposed schema can be accessible to public roles when grants allow it and RLS is absent. Both dashboards warn about this. Read the warnings.

Starting in test mode is fine for an afternoon. Shipping in test mode is the most common way small apps leak user data.

What a scan can and cannot tell you

WebAuditOS checks your site's public side: CORS, Content Security Policy and failing pages.

It cannot see Supabase policies or Firebase rules. Use each platform's security tools and test as an anonymous and a second user.

Neither choice is secure or insecure by itself. The rules you write decide.

Short answers

Is Supabase better than Firebase? For relational data and SQL, usually. For mobile offline sync, Firebase is stronger.

Is Supabase cheaper? It depends on usage. Firestore's per-operation pricing can cost more for read-heavy apps.

Can I move from Firebase to Supabase? Yes, Supabase documents migration paths, but data must be remodelled.

Which do AI app builders use? Many, such as Lovable and Bolt, use Supabase by default.

In the product

The checks this maps to

Every check named here runs on every scan, on every plan - what a plan changes is how many pages are crawled, how long the history is kept and what you can do with the result. These are the ids the findings carry, so you can match a line in a report to the explanation above.

sec.cors.wildcard - CORS is not wide open
sec.headers.csp - Content-Security-Policy header
tech.status.ok - Page returns a successful status

Run a free audit See a full sample report See the whole check library