Supabase vs Firebase: Complete Review

What is Supabase?

Supabase is an open-source Firebase alternative built on PostgreSQL. It provides real-time database, authentication, file storage, and edge functions—all the backend primitives you need for a full-stack app.

The key differentiator: it's built on PostgreSQL (a proven relational database) rather than Firebase's proprietary NoSQL approach.

Real-Time Database Comparison

I built a collaborative note-taking app in both Firebase and Supabase to compare real-time capabilities:

Winner: Supabase scales better and costs less. Firebase is easier for absolute beginners.

Authentication & Security

Row Level Security (RLS)

This is Supabase's biggest advantage. RLS lets you define policies at the database level. For example, users can only see their own posts. This is built-in, not an afterthought.

OAuth Integrations

Both support Google, GitHub, Discord, etc. Supabase has slightly fewer integrations than Firebase, but covers 95% of use cases.

Email Templates

Supabase lets you customize password reset and email confirmation templates. Firebase is more limited here.

Pricing Deep Dive

For production apps: Supabase becomes cheaper at scale. Firebase charges per read/write. Supabase charges per database size + function calls.

Performance & Latency

I ran latency tests on a simple query (select * from users where id = X):

Supabase edges out Firebase for direct query performance. Both are fast enough for production.

Final Verdict

Use Firebase if: You want maximum speed to production and don't mind paying for scale.

Use Supabase if: You want a relational database, better pricing at scale, and more control over data access via RLS.

For my projects, I default to Supabase. The developer experience is excellent, and RLS gives me peace of mind for data security.