This is the backend decision that keeps indie hackers up at night. Firebase has been the default "just ship it" backend for years. Supabase arrived as the open-source alternative and has been gaining ground fast. Both are excellent. The right choice depends on what you're building.

We've built projects with both. Here's what we actually think, not what either company's marketing team wants you to hear.

The fundamental difference

Firebase uses a NoSQL document database (Firestore). Supabase uses PostgreSQL, a traditional relational database. This single difference cascades into almost every other comparison point.

If you've worked with SQL before, Supabase will feel natural. If you've mostly built with JavaScript and prefer flexible, schema-less data, Firebase will feel more intuitive. Neither approach is wrong. They're optimised for different mindsets.

Database and querying

Supabase (PostgreSQL)

Supabase gives you a full Postgres database with all the power that implies. Joins, views, stored procedures, triggers, full-text search. If your data has relationships (users have posts, posts have comments), Supabase handles this naturally.

The query builder is clean and feels like writing SQL without actually writing SQL. But if you want raw SQL, you can run that too. The Table Editor in the dashboard lets you manage data visually, which is great for debugging.

Firebase (Firestore)

Firestore stores data as documents in collections. It's flexible: you can add fields without migrations, nest data inside documents, and start writing data immediately without defining a schema.

The trade-off is querying. Complex queries with multiple conditions, sorting, and filtering can be awkward. There are no joins. If you need data from two collections together, you're making multiple queries and combining them in your application code. For simple apps, this is fine. For complex data models, it becomes painful.

Authentication

Both handle auth well. Firebase Auth has been around longer and supports more providers out of the box (Google, Apple, Facebook, Twitter, phone, email, anonymous). It's battle-tested at massive scale.

Supabase Auth is newer but covers the essentials: email/password, magic links, OAuth providers (Google, GitHub, Discord, etc.), and phone auth. It integrates directly with your Postgres database via Row Level Security, which is a powerful pattern for securing data without writing backend code.

Winner: Firebase by a slight margin for variety of providers. Supabase wins on the security model integration.

Real-time capabilities

Firebase was built around real-time from day one. Firestore's real-time listeners are fast, reliable, and well-documented. If you're building a chat app, collaborative editor, or anything that needs instant updates, Firebase still has the edge here.

Supabase added real-time subscriptions via Postgres's built-in replication features. It works, and it's improving rapidly, but it's not as mature or as performant as Firebase's real-time system for high-frequency updates.

Storage

Both offer file storage with similar APIs. Firebase Storage is backed by Google Cloud Storage. Supabase Storage is S3-compatible and includes built-in image transformations (resizing, cropping) which is a nice touch that saves you from needing a separate image processing service.

Pricing

This is where things get interesting. Firebase pricing is usage-based, which sounds fair until you get a surprise bill. Firestore charges per read, write, and delete operation. A poorly optimised query in a loop can cost real money. Many indie hackers have stories about unexpected Firebase bills.

Supabase uses more predictable pricing. The free tier is generous (500MB database, 1GB storage, 2GB bandwidth). The Pro plan at $25/month gives you 8GB database, 100GB storage, and 250GB bandwidth. You know what you're paying before you get the bill.

For side projects and MVPs, both free tiers work. For growing products, Supabase's pricing is more predictable. Firebase can be cheaper at very small scale but more expensive as you grow, depending on your read/write patterns.

Developer experience

Firebase's SDK is polished and well-documented. Google has invested heavily in tutorials, sample projects, and community resources. If you get stuck, there's almost certainly a Stack Overflow answer or YouTube video covering your exact issue.

Supabase's developer experience has improved dramatically. The dashboard is excellent, the documentation is clear, and the JavaScript client library is intuitive. The community is smaller but growing fast, and the team is responsive on GitHub and Discord.

One thing Supabase gets right: because it's Postgres underneath, the skills you learn are transferable. If you outgrow Supabase, you can take your database anywhere. With Firebase, you're locked into Google's ecosystem.

Edge functions and serverless

Firebase Cloud Functions run on Google Cloud and support Node.js, Python, and more. They're well-integrated with Firebase events (new user created, document updated) and work reliably at scale.

Supabase Edge Functions run on Deno and are deployed globally. They're faster to cold-start than Firebase Functions and work well for API endpoints, webhooks, and custom logic. The Deno runtime is a minor learning curve if you're used to Node.js, but it's clean and modern.

When to choose Supabase

  • You have relational data (users, posts, comments, orders)
  • You want SQL and the power of PostgreSQL
  • Predictable pricing matters to you
  • You value open source and portability
  • You want auth tightly integrated with database security
  • You're building a SaaS, marketplace, or data-heavy application

When to choose Firebase

  • You need best-in-class real-time syncing
  • You're building a mobile app (Firebase's mobile SDKs are excellent)
  • You prefer NoSQL and flexible schemas
  • You need advanced auth providers (phone, anonymous, multi-factor)
  • You're already in the Google Cloud ecosystem
  • You're building a chat app, game, or anything with heavy real-time requirements

Our recommendation

For most web applications in 2025, we'd pick Supabase. The combination of Postgres, predictable pricing, and the open-source model makes it the safer long-term bet. You get a real database with real SQL, and you're not locked into any vendor.

Firebase is still the better choice for mobile-first apps and anything where real-time performance is the primary concern. It's also a great choice if you're already using Google Cloud services.

For the full feature-by-feature comparison, check our Supabase vs Firebase comparison page. And if you're building an MVP and want to see how these fit into a complete stack, try the Stack CardNewStack Builder.