Firebase vs Supabase: Which Backend for Your App?
Choose Firebase if you want Google's mature mobile toolkit (offline-first Firestore sync, push messaging, Crashlytics, analytics and A/B testing) in one console and your data fits a document model. Choose Supabase if you want a relational Postgres database with SQL, row-level security, an open-source stack you can self-host, and pricing tied to compute rather than per-document reads. Both handle auth, storage, functions and realtime well.
- Firebase's main database, Cloud Firestore, is a NoSQL document store; Supabase gives every project a full Postgres database.
- Firebase now also offers Postgres through Firebase SQL Connect (formerly Data Connect), backed by Cloud SQL.
- Firestore has built-in offline persistence on mobile and web, a real advantage for field and spotty-connection apps.
- Supabase is open source and self-hostable, which lowers lock-in; Firebase runs only on Google Cloud.
- Firebase bills by operations like document reads and writes; Supabase bills a plan fee plus per-project compute and usage.
At a Glance
| Factor | Firebase | Supabase |
|---|---|---|
| Primary database | Cloud Firestore (NoSQL documents) | PostgreSQL (relational) |
| SQL option | Firebase SQL Connect on Cloud SQL | Native, full SQL |
| Offline sync | Built into Firestore SDKs | Not built in; add a sync tool |
| Access control | Firebase Security Rules | Postgres Row Level Security |
| Push, crash reports, analytics | Built in, largely free | Use separate services |
| Open source and self-hosting | No, Google Cloud only | Yes, open source and self-hostable |
| Pricing model | Free tier, then pay per operation and usage | Plan fee plus per-project compute and usage |
| Best fit | Mobile-first, offline, simple data shapes | Relational data, SQL, reporting, portability |
Choose Firebase if you are building a mobile-first app that needs offline sync, push, crash reporting and analytics in one place, and your data fits documents. Choose Supabase if your data is relational, you want SQL and reporting, or you value open source and the option to self-host.
What Each Platform Is
Both are backend-as-a-service platforms: they give your app a database, user authentication, file storage, server-side functions and realtime updates without you running servers. That can remove a large part of the backend work in a new app.
Firebase is Google's app development platform. Its core pieces are Cloud Firestore (a NoSQL document database), Firebase Authentication, Cloud Storage, Cloud Functions, Firebase Hosting and App Hosting, plus a set of app-quality and growth tools: Cloud Messaging for push notifications, Crashlytics, Analytics, Remote Config and A/B Testing. Firebase SQL Connect, the renamed Data Connect, adds a managed PostgreSQL option through Cloud SQL with a GraphQL-based schema.
Supabase is an open-source platform built around PostgreSQL. Each project is a full Postgres database with auto-generated APIs, Auth, Storage, Realtime, Edge Functions (written in TypeScript on Deno) and a vector database via pgvector. You can use Supabase's hosted service or self-host the stack.
Data Model: Documents vs Relational Tables
This is the most important technical difference. Firestore stores data as collections of JSON-like documents. It is fast and simple for data you read in predictable shapes, such as a user profile, a chat thread or a feed. It is less suited to complex queries across many related records; you typically duplicate data to fit how screens read it.
Supabase uses relational tables with SQL joins, foreign keys, transactions and views. If your app has orders, customers, invoices, appointments and staff that all relate to each other, or you need reporting, a relational database is usually the more natural fit. Your data also lives in standard Postgres, which almost every analytics and reporting tool can connect to.
Both platforms also fit well with modern app frameworks. Firebase has official SDKs for iOS, Android, the web, Flutter and Unity, and widely used React Native libraries. Supabase's documentation covers client libraries for JavaScript, Flutter, Swift, Kotlin, Python and C#, and because it is Postgres underneath, any server-side language can talk to it directly.
Offline, Realtime and Mobile Features
Firestore's client SDKs include offline persistence: the app keeps working without a connection and syncs changes when it reconnects. For field service, inspections, delivery or any app used in buildings with poor signal, that is a significant head start. Supabase does not include an equivalent offline sync layer out of the box; teams add one with a third-party sync tool or build their own caching.
Both offer realtime updates. Firestore listeners push changes to subscribed clients. Supabase Realtime broadcasts database changes, ad hoc messages and user presence. For push notifications, Firebase Cloud Messaging is built in and free; Supabase apps typically use FCM, Apple Push Notification service or a service like Expo's push API directly.
Security Model
Because client apps talk to these databases directly, access control is the critical piece. Firebase uses Security Rules, a declarative language that checks each read and write. Supabase uses Postgres Row Level Security policies written in SQL. Both are powerful; both are a common source of data leaks when left too open. Test rules or policies as carefully as application code, and never ship with permissive test settings. Our guide on securing a mobile app covers the broader checklist.
For regulated data, check each platform's current compliance documentation and whether it will sign the agreements you need, such as a HIPAA business associate agreement, on the plan you intend to use.
Pricing Model and Lock-In
Firebase has a no-cost Spark plan and a pay-as-you-go Blaze plan. Firestore charges by operations (document reads, writes and deletes) plus storage and network. That is economical for many apps but can surprise teams whose screens read large numbers of documents, so model your read patterns early. Several Firebase tools, including Analytics, Crashlytics and Cloud Messaging, are free.
Supabase has Free, Pro, Team and Enterprise plans. Paid plans combine a subscription with hourly compute for each project and usage-based charges for items like egress, storage and monthly active users. Free projects pause after a period of inactivity, so do not run production on the free tier.
On lock-in, Supabase's open-source stack and standard Postgres make migration comparatively straightforward. Firestore data and Security Rules are specific to Firebase, so moving off it means reworking the data layer. Both choices are reasonable; just make the tradeoff on purpose. See what is a tech stack for how the backend fits the rest of your app, or our app development overview.
Sources and Further Reading
We link to the primary documentation so you can verify the details yourself.
- Firebase pricing, Firebase (Google)
- Access data offline, Firebase documentation (Google)
- Firebase SQL Connect, Firebase documentation (Google)
- Supabase pricing, Supabase
- Row Level Security, Supabase documentation
- Self-hosting Supabase, Supabase documentation
Related Questions
Can I switch from Firebase to Supabase later?
Yes, but plan for real work. Firestore documents need to be restructured into relational tables, Security Rules rewritten as Row Level Security policies, and client code updated. Auth users can be migrated with some care. It is easier early than after years of growth.
Which one is cheaper?
It depends on usage shape. Firestore bills per document read and write, so read-heavy screens can get expensive, while Supabase bills mostly for compute and storage. Estimate your monthly operations and data size on both official pricing pages before deciding.
Do I need a backend developer with either platform?
Less than with a custom server, but yes for anything serious. Someone needs to design the data model, write and test security rules or policies, build server functions for sensitive logic, and set up backups and monitoring.
Can Supabase or Firebase power AI features?
Both can. Supabase includes pgvector for storing embeddings and running similarity search in Postgres. Firebase offers vector search in Firestore and integrates with Google's Gemini models through Firebase AI Logic. Either can call outside AI APIs from server functions.