Supabase vs Firebase
Both promise a backend without writing one. One gives you Postgres and the freedom to leave; the other gives you Firestore and a long-term Google relationship. I’ve shipped products on both — here’s the truth.
In 2026, pick Supabase by default. Postgres is the right database for almost every product, Row Level Security is the right authorisation model, and the open-source stack means you can self-host if a customer demands it. Firebase only wins when you’re building a mobile-first app where Firestore’s offline sync genuinely is the killer feature — and even then, expect to fight Firestore’s query model the moment your data gets interesting.
You want a real relational database, foreign keys, joins, full-text search, and the ability to leave. Most web apps, internal tools, AI products and SaaS dashboards.
You're shipping a mobile app where offline-first sync is the entire point, you’re already deep in Google Cloud, or you need Firebase Authentication's phone auth at scale.
Side-by-side, line by line
Both products bundle auth, database, storage, realtime and serverless functions. The interesting differences live in the database model and the long-term economics.
| Feature | Supabase | Firebase |
|---|---|---|
| Database | EdgePostgres 15+. Joins, transactions, foreign keys, JSONB, extensions. | Firestore (NoSQL document) or RTDB (JSON tree). No joins. |
| Free tier | 500MB DB, 1GB storage, 50k MAUs, 2 projects. | EdgeGenerous Spark plan: 1GB Firestore, 10GB egress/month, 50k MAUs. |
| Pricing at scale | EdgePro $25/mo + usage. Predictable. | Pay-as-you-go. Reads and writes per document — easy to overspend. |
| Auth | Email, OAuth, magic link, phone, SSO. JWT-based. | EdgeSame plus Apple/Game Center. Best phone auth in the industry. |
| Authorisation | EdgeRow Level Security in Postgres. Declarative, audit-friendly. | Firestore security rules. Powerful but scattered and easy to get wrong. |
| Realtime | Postgres replication + Phoenix channels. Solid for web. | EdgeFirestore listeners. Battle-tested, especially on mobile. |
| Offline sync | Not really. Use a sync layer on top. | EdgeFirst-class. The reason Firebase still exists for mobile. |
| Querying | EdgeFull SQL. Joins, CTEs, window functions, full-text search. | Index every query. No joins. Composite indexes per query shape. |
| Edge functions | Deno-based, Postgres-aware, scoped to project. | EdgeCloud Functions for Firebase. Node, Python — broader but heavier. |
| Vendor lock-in | EdgeOpen source. Self-host any time. Postgres dump = full migration. | Total. Firestore is a proprietary database with no real export path. |
| AI / vector search | Edgepgvector built in. Native RAG support. | Vector Search via separate Vertex AI integration. |
| Multi-region | Read replicas, single primary. | EdgeMulti-region Firestore replication built in. |
Supabase
- It's Postgres. Every senior engineer you ever hire already knows it.
- Row Level Security is the cleanest way to enforce authorisation in any backend.
- Open source. Self-hostable. Real exit strategy on day one.
- pgvector means RAG and AI features are a CREATE EXTENSION away.
- Pricing is predictable. $25/month covers most early-stage SaaS.
- Realtime can wobble under heavy fan-out — design around it for big presence apps.
- Multi-region is read replicas only, not active-active.
- Edge Functions are Deno-only and feel less mature than Vercel/Cloudflare.
- You're still responsible for picking sensible RLS policies.
Firebase
- Best-in-class offline sync — the killer feature for mobile apps.
- Phone authentication at global scale, basically untouchable.
- Auto-scales effortlessly to absurd load with no config.
- Tight integration with the rest of Google Cloud (Vertex AI, BigQuery, etc.).
- Firestore’s query model is a straitjacket once your data has shape.
- Pricing per read/write means a single hot loop can rack up real money overnight.
- No real "leave Firebase" plan. Migrations are full rewrites.
- Security rules are powerful but easy to misconfigure and hard to test.
- Long-term Google product confidence is… let's say "not what it was".
Supabase
- Building a SaaS product, B2B tool or anything with relational data.
- You need full-text search, complex queries, or analytics over your own data.
- Compliance, GDPR, or enterprise customers might require self-hosting.
- You're building anything AI-shaped — pgvector is genuinely a superpower.
- You want predictable monthly costs not tied to per-document reads.
- You like being able to ssh into your own database and run a query.
Firebase
- You're building an iOS or Android app where offline-first is non-negotiable.
- You need phone authentication with the highest reliability available.
- You're already invested in Google Cloud / Vertex AI / BigQuery.
- Your app has predominantly key-value style data with simple access patterns.
- You're a solo dev who never wants to think about a database again.
What I ship in 2026
Every web project I start now goes on Supabase. Not because Firebase is bad — it isn’t — but because the moment your app has more than three entities that relate to each other, Firestore becomes a denormalisation maze. I’ve watched startups burn entire quarters because they picked Firestore for a relational problem and then had to maintain 14 different "view collections" hand-synced by Cloud Functions. Postgres makes that whole class of problem go away.
The one project type where I still reach for Firebase is mobile-first apps with hard offline requirements — think delivery apps, field service tools, anything used on a dodgy 3G connection. Firestore’s offline cache and conflict resolution are still the best in the business, and rebuilding that on top of Postgres is real work. If that’s your context, pick Firebase. Otherwise, Supabase.
Pricing should also be on the table. A modest production app on Firebase often lands around $200–$400 a month once you factor in Firestore reads, Cloud Functions and Cloud Storage egress. The same workload on Supabase Pro is $25 plus a few quid in compute. That difference funds an entire week of engineering time, every month, forever.
The honest conclusion
Firebase was the right answer in 2018. In 2026, picking it is a default that you should be able to defend out loud. Supabase isn’t perfect — realtime fan-out, global writes and Edge Functions all have rough edges — but the fundamental choice of "Postgres + open source" beats "Firestore + Google" for the overwhelming majority of products being built right now.
Still not sure which to pick?
I make these calls every week on real projects. If you want a straight answer for your stack — not a list of trade-offs — get in touch.