A practical comparison after migrating 12 projects. Real costs, scaling limits, and when to switch.
By David Friedman, Founder of AppBrewers
I have built 50+ projects on Firebase and migrated 12 of them to Supabase. Both are excellent. Both will fail you at scale if you choose wrong. Here is what I wish I knew before picking either.
The Short Answer
| Factor | Firebase | Supabase | Winner |
|---|---|---|---|
| Setup speed | 5 minutes | 10 minutes | Firebase |
| Real-time | Built-in | Built-in | Tie |
| SQL queries | Limited | Full PostgreSQL | Supabase |
| Self-hosting | No | Yes | Supabase |
| Vendor lock-in | High | Low | Supabase |
| Cost at scale | Expensive | Cheaper | Supabase |
| Documentation | Excellent | Good | Firebase |
| Community | Massive | Growing | Firebase |
Choose Firebase if: You want to ship fast and do not care about vendor lock-in.
Choose Supabase if: You need SQL, self-hosting, or want to avoid Google.
When Firebase Wins
1. Speed of Development
Firebase Auth works in 5 lines of code. Firestore reads in 3. Cloud Functions deploy in 30 seconds. For MVPs, this is unbeatable.
2. Real-Time Everything
Firestore real-time sync works out of the box. No WebSocket setup. No event sourcing. Just listen to a collection and get updates.
3. Google Ecosystem
If you use Google Analytics, Google Ads, Google Workspace — Firebase integrates seamlessly.
4. Firebase App Hosting
Next.js 15 deploys with one command. Edge caching, automatic scaling, zero config. Hosting costs start at free.
When Supabase Wins
1. PostgreSQL
You get real SQL. Joins, aggregates, window functions, CTEs. Firestore is a document database — complex queries require client-side processing or Cloud Functions.
2. No Vendor Lock-in
Supabase is open source. You can self-host. You can export your database and run it on AWS, DigitalOcean, or your own server. Firebase locks you into Google.
3. Cost at Scale
Firestore charges per read/write. At 1M reads/day, you pay $1.80/day. Supabase charges by compute — $25/month for 2GB RAM, unlimited reads.
4. Row-Level Security
Supabase RLS uses PostgreSQL policies. More powerful, more flexible, and easier to audit than Firestore security rules.
Real Costs at Scale
Scenario: 10,000 Daily Active Users
| Cost | Firebase | Supabase |
|---|---|---|
| Database | $200-400/month | $25-75/month |
| Auth | $0 (included) | $0 (included) |
| Storage | $50-100/month | $25-50/month |
| Functions | $50-100/month | $0 (included) |
| Hosting | $0-25/month | $0-25/month |
| Total | $300-625/month | $50-175/month |
Firebase is 3-4x more expensive at scale. The tradeoff: you ship 2x faster.
Migration Story
We migrated a SaaS platform from Firebase to Supabase last year.
Why:
- Firestore queries became too complex
- Costs hit $800/month
- Needed self-hosting for enterprise clients
How long: 3 weeks
Cost: €12,000
Result: $600/month savings, happier enterprise clients
Would we do it again? Only if we hit scale. For MVPs, Firebase is still faster.
The Hidden Costs
Firebase
- Cold starts: Cloud Functions take 2-5 seconds on first call
- Query limitations: No native joins, limited sorting
- Vendor lock-in: Cannot self-host Firestore
- Documentation gaps: Advanced features poorly documented
Supabase
- Smaller community: Fewer Stack Overflow answers
- Realtime limits: 200 concurrent connections on free tier
- Edge functions: Less mature than Firebase Functions
- Migration complexity: Moving from Firebase requires data export
Our Recommendation by Stage
| Stage | Users | Recommendation | Why |
|---|---|---|---|
| MVP | 0-1,000 | Firebase | Ship in 2 weeks |
| Growth | 1,000-10,000 | Firebase | Still fast, still cheap |
| Scale | 10,000-50,000 | Supabase | SQL queries, cost savings |
| Enterprise | 50,000+ | Supabase | Self-hosting, compliance |
What We Use at AppBrewers
| Project | Stack | Why |
|---|---|---|
| Client MVPs | Next.js + Firebase | Speed matters most |
| SaaS platforms | Next.js + Firebase | Real-time, auth, hosting in one |
| Enterprise clients | Next.js + Supabase | Self-hosting, SQL, compliance |
| Internal tools | Next.js + Supabase | Cost-effective, PostgreSQL |
Questions to Ask Before Choosing
- Do you need complex SQL queries? → Supabase
- Do you need to ship in 2 weeks? → Firebase
- Do you care about vendor lock-in? → Supabase
- Do you use other Google services? → Firebase
- Is cost a concern at scale? → Supabase
Need Help Choosing?
We have built on both. Tell us your project and we will recommend the right stack.
Originally published on the AppBrewers Blog.
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