Supabase vs Firebase in 2026: I Built the Same SaaS Product with Both
I built the same SaaS on both platforms. One cost $25/month. The other sent me an $847 bill. PostgreSQL vs Firestore, real-time sync, vendor lock-in.
The short answer
Choose Supabase in 2026 unless you have a specific reason to use Firebase. Supabase gives you PostgreSQL (a real database you own), predictable pricing, and an open-source core you can self-host. Firebase still wins on real-time sync simplicity, but for most new projects, Supabase is the better default. I built the same SaaS product on both platforms over four weeks. One cost me $25 per month at launch. The other handed me an $847 bill after a Product Hunt feature. Here is everything I learned.
What each platform actually is
Firebase is Google's Backend-as-a-Service: NoSQL Firestore, auth, storage, functions, real-time sync. The pitch is simplicity: write frontend code, Firebase handles the backend. You never touch a server or write a migration.
Supabase is the open-source Firebase alternative on PostgreSQL: full Postgres, auth, storage, edge functions, real-time. The pitch is control: real SQL, standard migrations, export anytime, self-host anywhere.
The philosophical difference matters. Firebase wants you in Google's ecosystem. Supabase wants to be replaceable. When a platform's business model is "we hope you never leave," every design decision reflects that incentive.
Supabase gives you a full SQL editor, table viewer, and API explorer. Connect any Postgres client directly.
Pricing: where Firebase hurts
| Resource | Firebase (Blaze) | Supabase (Pro) |
|---|---|---|
| Database reads | $0.06 per 100K | $25/month included |
| Database writes | $0.18 per 100K | Included in Pro |
| Database deletes | $0.02 per 100K | Included in Pro |
| File storage | $0.026/GB + $0.12/GB dl | $0.021/GB, 100GB dl incl. |
| Monthly base | $0 (pay-as-you-go) | $25 (fixed) |
My SaaS: normal day with 200 users, Firebase cost $2/day, Supabase $25/month flat. Then Product Hunt feature. Firebase bill: $847. Supabase: $25 plus $10 storage overage. Same app, same traffic. $800 difference for one month.
Firebase charges per read/write/delete. One user action updating a document and triggering a Cloud Function costs 4 reads + 1 write. At scale, you pay real money for what Supabase includes in base price.
PostgreSQL vs Firestore
Firestore is NoSQL: collections of JSON documents, no joins, no foreign keys, no schema. Fast for simple queries, painful for complex ones. Finding "tasks assigned to my team, grouped by project, sorted by priority" requires three queries and client-side merging in Firestore. In Supabase, it is one SQL query with two JOINs.
I hit this wall on day 4 of the Firebase build. The Supabase query was 5 lines of SQL. The Firebase solution was 40 lines of JavaScript, harder to debug, and slower at scale. PostgreSQL has solved relational queries efficiently for 30 years.
Real-time: Firebase's last stronghold
Firebase real-time sync is still best-in-class: subscribe to a document, updates push to all clients under 100ms, automatic offline persistence and conflict resolution. Supabase real-time uses PostgreSQL logical replication, works well for simple cases but lacks built-in offline persistence.
For my task manager, both worked fine at 100 to 200ms latency. The difference only matters for Google Docs competitors or multiplayer games.
Vendor lock-in
Firebase stores data in proprietary format. No standard SQL export. Functions tied to Google runtime. Security rules are Firebase-specific. Leaving means a months-long migration project.
Supabase stores data in PostgreSQL. Run pg_dump anytime for a complete SQL backup. Deploy to any Postgres host with zero code changes. If Supabase disappeared tomorrow, your data survives independently.
I learned this with Parse in 2016 when Facebook shut it down: six weeks to migrate. I now ask every provider: "If you shut down, how long to leave?" Supabase: run pg_dump. Firebase: months of engineering.
Final Recommendation
Use Supabase if: starting a new project in 2026, want predictable pricing, value the ability to leave, need relational queries, or want self-hosting options.
Use Firebase if: need best-in-class real-time with offline persistence, deeply integrated with Google Cloud, building a quick prototype with NoSQL flexibility, or staying under 50K reads/day.
My choice: I migrated from Firebase to Supabase after the $847 bill. The migration took a weekend. I have built three more projects on Supabase since. The PostgreSQL advantage alone is worth the switch.
Frequently asked questions
Can I use Supabase with React Native or Flutter?
Yes. Official client libraries for JavaScript/TypeScript, Flutter, Swift, Kotlin, and Python. JS client is most mature.
Does Supabase have Firebase-like realtime listeners?
Yes, via PostgreSQL replication. Subscribe to table changes with channel subscriptions. Slightly more verbose than Firebase onSnapshot but functionally equivalent.
What about serverless functions?
Both comparable for simple use cases (emails, webhooks, image resizing). Supabase Edge Functions run on Deno for faster cold starts. Firebase Cloud Functions (full Node.js) handle heavy dependencies better.
Is Supabase actually free?
Free tier: 500MB database, 5GB bandwidth, 1GB storage, 50K MAU. Enough to build and launch most SaaS products. Upgrade to Pro ($25/month) when exceeding limits or needing nightly backups.
