Supabase vs Firebase Cost Calculator

Firestore bills per document read — not per query. If your app loads a list of 500 items every time a user opens the page, that is 500 reads per page load. With 10,000 daily active users opening the page twice per day, that is 10 million reads per day — 10 million minus the 50,000 free daily reads = 9,950,000 billable reads = $5.97/day = $179/month from a single poorly designed query. Supabase charges no per-query or per-row fee — the same query costs nothing extra regardless of how many rows it returns.

Firebase wins for native Android and iOS mobile apps. It has more mature mobile SDKs, offline sync built in, Crashlytics for crash reporting, Google Analytics integration, Remote Config for feature flags, and App Distribution for beta testing. Supabase has decent mobile SDKs but the ecosystem is not as mature for mobile-specific needs. For React Native or Flutter apps, both work reasonably well. For Swift or Kotlin native apps, Firebase is the safer choice.

Starting February 3, 2026, Firebase Cloud Storage requires a Blaze (pay-as-you-go) billing plan — even if your storage usage is within the free tier limits. Previously, Spark plan users could use Firebase Storage for free up to 1 GB. Now all Storage users must have a credit card on file and be on the Blaze plan. This forced many apps to either add billing information, switch to Supabase Storage, or migrate to other storage providers like AWS S3 or Cloudflare R2.

Yes — Supabase free projects are paused after 7 consecutive days of inactivity (no API calls or database connections). When paused, your data is preserved but the project is inaccessible until manually resumed from the Supabase dashboard. This is a significant limitation for production apps. If you need always-on availability, you must upgrade to Supabase Pro ($25/month). Firebase does not have project pausing — it is always on.

Migrating from Firebase to Supabase is non-trivial but doable. The main challenge is the data model difference — Firestore is a document database while Supabase uses PostgreSQL. You need to redesign your data schema into relational tables. Auth migration requires exporting Firebase users and importing them to Supabase — passwords cannot be migrated and users need to reset passwords. Storage migration is simpler — direct file transfer. Plan for 2-6 weeks of migration work depending on app complexity. Supabase provides migration guides in their documentation.