Supabase vs Firebase: which backend should you choose?

The Short Version

Firebase (by Google) is a managed backend with a NoSQL document database (Firestore). Supabase is an open-source backend built on PostgreSQL. Both give you auth, storage, real-time, and serverless functions — but they differ fundamentally in data model, pricing, and vendor lock-in.

Architecture Comparison:

  Firebase                          Supabase
  +-----------------------+        +-----------------------+
  |  Google Cloud (locked) |        |  Postgres (portable)   |
  |  +-----------------+  |        |  +-----------------+  |
  |  | Firestore (NoSQL)|  |        |  | PostgreSQL (SQL) |  |
  |  | Document-based   |  |        |  | Relational       |  |
  |  +-----------------+  |        |  +-----------------+  |
  |  | Pay per read     |  |        |  | No per-request $  |  |
  |  +-----------------+  |        |  +-----------------+  |
  |  | Cannot self-host |  |        |  | Self-host w/ Docker|  |
  |  +-----------------+  |        |  +-----------------+  |
  +-----------------------+        +-----------------------+

Database Model

Firebase uses Cloud Firestore, a schemaless NoSQL document database. Data is stored as JSON-like documents grouped in collections. This makes prototyping fast, but as relationships grow complex, you end up denormalizing data or handling joins in your application code.

Supabase uses PostgreSQL — a full relational database with foreign keys, indexes, ACID transactions, and SQL. You get joins, subqueries, window functions, and stored procedures from day one.

If your data is highly relational (users, orders, products, invoices), SQL is the natural fit. If your data is document-shaped and changes frequently, Firestore's flexibility helps.

Source: [Supabase — Supabase vs Firebase](https://supabase.com/alternatives/supabase-vs-firebase), [Bytebase — Supabase vs Firebase](https://www.bytebase.com/blog/supabase-vs-firebase/)

Pricing Comparison

Firebase's pay-per-read model can surprise you as your app grows — every document read, write, and listener adds to the bill. Supabase doesn't charge per API request, which makes budgeting simpler.

Source: [Supabase Pricing](https://supabase.com/pricing), [Firebase Pricing](https://firebase.google.com/pricing)

Real-World Cost at Scale

The pricing table above tells you the theory. Here's what it looks like in practice.

A startup with 10,000 daily active users and moderate database activity:

Monthly Cost at 10K DAU:

  Firebase:   $500-1500/month    ████████████████████
  Supabase:   $50-100/month       ██

Firebase's per-read pricing is the culprit. Every document read, every listener connection, every write operation adds up. A social feed app where each user loads 50 documents per session generates 500,000 reads per day — that's already over the free tier before lunch.

Supabase's $25 Pro plan includes unlimited API requests. You pay for storage and compute, not per request. This is why most teams migrating from Firebase to Supabase cite cost as the primary driver.

Source: [Justin McKelvey — Supabase vs Firebase 2026: The Honest Verdict](https://justinmckelvey.com/blog/supabase-vs-firebase), [Bytebase — Supabase vs Firebase: Complete Comparison](https://www.bytebase.com/blog/supabase-vs-firebase/)

The Vendor Lock-In Question

Firebase is proprietary. You cannot self-host it. Your data lives in Firestore (NoSQL), your auth in Google Identity Platform, your functions in Google Cloud Functions. Every layer is Google-owned.

If you decide to leave Firebase, you face:

1. 1Data migration — Firestore documents must be restructured into a relational model or a different NoSQL format. There is no "export to SQL" button.
2. 2Auth migration — Firebase Auth tokens and user sessions don't transfer. Users may need to reset passwords.
3. 3Function rewrites — Firebase Cloud Functions use a Google-specific SDK. Moving to AWS Lambda or Supabase Edge Functions means rewriting the function layer.
4. 4Client SDK swap — Your frontend code uses Firebase SDKs. Every API call, every listener, every auth call needs to be rewritten.

Developers on Reddit and dev.to consistently report that Firestore's vendor lock-in "creeps up" — it's not painful at the start, but by the time you want to leave, the migration cost is enormous.

Supabase, by contrast, runs on PostgreSQL. If Supabase Cloud disappears tomorrow, you spin up Postgres anywhere — AWS RDS, DigitalOcean, your laptop. The SQL dump works. The schema works. The data works. Zero rewrite needed.

Source: [dev.to — Why I Switched Away from Google Firestore](https://dev.to/spencerpauly/why-i-switched-away-from-google-firestore-3pn), [Encore — Migrate from Firebase to AWS](https://encore.dev/articles/migrate-firebase-to-aws)

Authentication

Both platforms offer email/password, OAuth providers (Google, GitHub, Apple), and phone auth.

Firebase requires upgrading to Identity Platform for enterprise features like SAML/OIDC and MFA.

Supabase includes SSO, SAML, and OIDC on Pro and Enterprise plans without changing SDKs. Access control is handled through Row-Level Security (RLS) policies written in SQL — the same language you use for your data.

Storage

Firebase uses Google Cloud Storage with separate pricing for storage, bandwidth, and operations. No built-in image transformations (you need Firebase Extensions).

Supabase uses an S3-compatible object store integrated with Postgres. Storage metadata lives in a database table, so RLS policies apply to files too. Built-in image transformations and CDN delivery are included.

Open Source vs. Proprietary

Firebase is proprietary and hosted on Google Cloud. No self-hosting option. Tight vendor lock-in.

Supabase is fully open-source. You can inspect the code, contribute, and host it yourself with Docker. If Supabase Cloud disappears tomorrow, your database still works — it's just Postgres.

When to Choose Firebase

• Rapid prototyping with NoSQL flexibility
• Deep Google Cloud ecosystem integration (BigQuery, ML, etc.)
• Offline-first mobile apps (Firestore has built-in offline caching)
• You don't mind vendor lock-in

When to Choose Supabase

• Relational data with complex queries and joins
• You want predictable pricing without per-request charges
• Open source and self-hosting matter to you
• You need SQL's ACID guarantees
• You want AI/vector capabilities (Postgres has native vector support)

The Backup Reality for Both

No matter which you choose, your database is at risk. Firestore data can be accidentally deleted, and Firebase doesn't offer easy export-to-own-storage backups. Supabase runs on Postgres, which means you can back it up with standard SQL dumps — and that's exactly what Supakeep does.

Supakeep automates daily Supabase backups straight to your own Google Drive. If you're on Supabase, there's no excuse not to have your own backups.

Learn more in our Supabase backup best practices guide and our guide on why every Supabase project needs its own backups.

Related reading: NoSQL vs SQL: which database should you choose? and why every Supabase project needs its own backups.