Firebase vs Supabase: which backend-as-a-service fits your app?
Firebase and Supabase are backend platforms that bundle authentication, a database, file storage, serverless functions and realtime updates. Firebase is Google's platform, centred on Cloud Firestore, a NoSQL document database. Supabase is an open source platform built around a full PostgreSQL database, with auth, storage, realtime and edge functions around it.
The short answer
Choose Supabase when your data is relational, you want SQL and you value an open source stack you could self-host, because it is built on PostgreSQL. Choose Firebase when you are building a mobile-first app that benefits from offline sync, push messaging, crash reporting and tight Google integration. Both remove a lot of backend work for early-stage products.
Firebase vs Supabase at a glance
| Criterion | Firebase | Supabase |
|---|---|---|
| Database | Cloud Firestore NoSQL documents (plus Realtime Database) | Full PostgreSQL database |
| Querying | SDK queries with indexing; no SQL joins | SQL, joins, views and Postgres functions |
| Access control | Firebase Security Rules | Postgres row-level security policies |
| Realtime | Core strength, with offline sync in client SDKs | Realtime changes over Postgres and channels |
| Functions | Cloud Functions for Firebase | Edge Functions running on Deno |
| Mobile extras | Cloud Messaging, Crashlytics, Analytics, Remote Config | Fewer mobile-specific services |
| Open source | Proprietary Google service | Open source and self-hostable |
| Portability | Data model ties you to Firestore | Standard Postgres; export with common tools |
Choose Firebase when
- You are building a mobile app that must work offline and sync later
- You need push notifications, crash reporting and analytics in one place
- Data is naturally document-shaped, such as chat messages or user feeds
- You already use Google Cloud and want everything in one account
Choose Supabase when
- Your data has relationships and you want SQL joins and reporting
- You want to avoid lock-in and keep the option to self-host or move to any Postgres host
- You need Postgres extensions such as pgvector for AI search
- You prefer database-level row security over separate rules files
- A web app built with Next.js or React is the main product
NoSQL documents or PostgreSQL
This is the biggest difference. Firestore is quick to start with and scales automatically, but queries are limited compared with SQL, so data is often duplicated across documents to support each screen. Supabase gives you PostgreSQL, so relational modelling, joins and reporting work as they would in any SQL database. Firebase has added a Postgres-backed option, Data Connect, but its core developer experience still centres on Firestore.
Security model
Both let client apps talk to the database directly, so access rules are critical. Firebase uses Security Rules written in its own language. Supabase uses PostgreSQL row-level security, which lives in the database and applies to every query. Either is safe when rules are written and tested carefully, and dangerous when they are left open.
Lock-in and growth
Supabase's data is standard PostgreSQL, so you can move it to another host or connect a custom Node.js backend later. Leaving Firebase usually means remodelling data. That matters less for a small mobile app and more for a product expected to grow complex reporting and integrations.
Frequently asked questions
Is Supabase just an open source Firebase?
It offers similar building blocks, but the core is different: Supabase is a PostgreSQL database with services around it, while Firebase is built around NoSQL documents.
Which is better for a mobile app?
Firebase has more mobile-specific services and strong offline sync. Supabase works well for mobile too, especially when the data is relational, but you may add separate tools for push and crash reporting.
Can I add my own backend later?
Yes with either. With Supabase, a custom backend can connect directly to the same Postgres database. With Firebase, it uses the Admin SDK to read and write Firestore.
Still deciding?
Tell me about your product, users and constraints, and I will recommend the option that fits, even if it is not the one I use most.
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