Firebase vs Supabase (2026): Which Backend Should You Choose?

Firebase vs Supabase at a glance

The free tiers are not the same shape

These limits were checked against each project's official pricing documentation on October 5, 2026. Supabase also limits the Free plan to two active projects. Firebase allowances vary by product, so the Firestore figures above should not be treated as one quota for every Firebase service.

What happens when you outgrow free

This is the decision. Supabase Pro starts at $25 a month and that covers 100,000 monthly active users, 8 GB of disk and 250 GB of egress before any overage. You know what next month costs.

Firebase has no single flat paid tier. Moving from Spark to Blaze links the project to Cloud Billing and billable services charge by usage after their allowances. A quiet project can cost very little. A faulty loop or unexpected traffic can increase reads, writes, functions and bandwidth quickly, so configure budgets and product-level controls before launch.

Neither model is wrong. Predictable beats cheap when you are budgeting. Usage billing beats a floor when your app is quiet. Pick the one whose failure mode you can live with.

The technical split is simpler than the pricing

If your data is relational, Supabase will feel obvious and Firestore will feel like fighting the tool. If you are building a mobile app and want Authentication, Crashlytics and Cloud Messaging from one vendor with official Flutter plugins, Firebase is the shorter path.

The database choice matters more than the feature checklist

A booking system, store or SaaS product usually has relationships between users, teams, subscriptions, orders and permissions. PostgreSQL represents those relationships directly, supports joins and gives the team standard SQL. Supabase is usually easier to reason about for this kind of application.

Firestore stores documents inside collections. It works well when the app reads a known document shape, needs realtime listeners or must keep useful data available offline on mobile. It becomes less comfortable when a screen needs complex joins or reporting across many related records. Those queries often require denormalised data and additional indexes.

Security works differently

Supabase protects exposed database tables with PostgreSQL Row Level Security policies. Firebase uses Security Rules for Firestore, Storage and other client-accessible services. Neither platform is secure merely because authentication is enabled. Test access rules with multiple roles and keep service credentials out of the mobile or web client.

Scaling and lock-in

Firebase removes more infrastructure decisions and integrates tightly with Google services. That can make delivery faster, but an application built around Firestore queries, Security Rules and Firebase-specific services takes deliberate work to move. Supabase uses Postgres and can be self-hosted, which gives it a more conventional database exit path. Moving authentication, storage and functions still requires application changes, so it is not automatic portability.

Which one fits you

• A Flutter or mobile app — Firebase, for the official plugins alone.
• Relational data and real SQL — Supabase.
• You need a predictable monthly bill — Supabase Pro at $25.
• A side project you touch rarely — Firebase, since Supabase pauses it.
• You want an exit route — Supabase. It is Postgres, with self-hosting available.

How we compared them

We checked the official pricing, billing, Flutter setup and platform documentation for both products on October 5, 2026. We compared database design, client support, free allowances, the first paid step and the operational risks that change a real decision. We have not benchmarked the same production application on both platforms, so this page does not claim a universal performance winner.