In the Supabase vs Firebase decision, our judgment is this: pick Supabase when your data is relational and you want a Postgres exit. Pick Firebase when the product is mobile-first and real-time, and the team is front-end heavy. Firebase's Firestore documentation says data synchronization updates connected devices and that Firestore caches data so the app works offline, which is why it suits that profile. The vendor docs below are there to test the call, not to replace it.
If a backend choice is one of several stack decisions on your plate, Hire developers by tech stack: rates, vetting and interview guides covers the rest one by one.
Which one for your situation?
These picks are judgment, not measurements.
| Situation | Pick | Why |
|---|---|---|
| SaaS with accounts, invoices and reporting | Supabase | The data is relational, and plain Postgres is underneath |
| EU customers, residency questions from buyers | Supabase | Named European regions you choose per project, four of them in EU member states |
| Mobile app with live sync, small front-end team | Firebase | Firestore is a NoSQL database your mobile and web apps access directly through native SDKs |
| Prototype you may throw away | Either | Both have a free entry tier |
| You expect to leave the vendor one day | Supabase | Postgres data moves; see the lock-in section |
How do the data models differ: Firestore documents or Postgres tables?
Firestore stores documents, and Supabase gives you a Postgres database. Firebase's Firestore docs put it as "Store your data in documents, organized into collections." That's the whole fork. Documents suit data you read as one unit. Tables suit data you query across: customers, orders, invoices, and the reports that join them.
The old shorthand "Firebase is NoSQL only" is out of date. Firebase's docs now describe a relational option backed by Cloud SQL for PostgreSQL, with type-safe mobile and web SDKs. The page says Firebase Data Connect has been renamed Firebase SQL Connect. It doesn't state general availability on the page we read, so check the status before you plan around it.
That makes the real question narrower: do you want Postgres as the whole product, or as an add-on to a Google-shaped stack? For the deeper document-versus-relational tradeoffs, see how documents and tables differ in depth.
How does each one bill, and what does your first year look like?
All pricing below is as of October 2026, as the vendors' own pages describe it. We don't model a bill for you, because nobody can without your traffic.
Supabase's pricing page lists Free at $0/month, Pro from $25/month, Team from $599/month and Enterprise as custom. Free includes "500 MB database size" and "50,000 monthly active users", and "Free projects are paused after 1 week of inactivity". Pro includes "8 GB disk size per project" and "100,000 monthly active users (then $0.00325 per MAU)". Spend caps are on by default on Pro, and paid projects aren't paused for inactivity. The shape is a flat tier plus metered overage.
Firebase has two plans, per its pricing page. Spark needs no payment method. Blaze needs a billing account and gives you higher usage levels. The Firestore model is per operation: Firestore's pricing documentation says you're billed for "The number of documents you read, write, and delete" and "The number of index entries read to satisfy a query", with a "minimum charge of one document read for each query". The daily free quota is 50,000 reads, 20,000 writes, 20,000 deletes and 1 GiB of storage. The free quota applies to one database per project.
Supabase's own comparison page says that on Firebase "every document read, write or listener contributes to cost". That's a vendor's claim about a rival, but it matches Firebase's own documentation of per-operation billing.
Our judgment: a flat tier is easier to budget, and per-operation billing is easier to start on. Which one is cheaper depends on how chatty your app is. For the build side of the budget, see what an MVP costs in Europe.
Can you keep EU user data in the EU?
With Supabase, yes, and you pick the place. Supabase's regions documentation lists six European regions, four of them in EU member states (Ireland, Paris, Frankfurt, Stockholm). The other two are London and Zurich. The page says the general Europe region includes London and Zurich, which are not EU member states, so choose a specific region if compliance matters. It also says plainly: "Region selection is a data-location control, not proof of regulatory compliance."
Firebase works differently. Its project locations page says "This 'location for default Google Cloud resources' is an immutable setting". It covers the default Firestore database instance and, for older *.appspot.com buckets, the default Cloud Storage bucket. New default Storage buckets (*.firebasestorage.app) don't set it. Choose it once, correctly, on day one.
Firebase Authentication is the catch. Firebase's privacy documentation says: "The Firebase Authentication service is run only from US data centers. As a result, Firebase Authentication processes data exclusively in the United States." Services such as Firestore, Functions, Storage and Hosting, among others, let you select a location. If your login records are in scope for your EU data question, that matters. The same page says customers typically act as controllers and Google as processor, with Data Processing and Security Terms, and the page links Standard Contractual Clauses. Whether that satisfies your lawyer is your lawyer's call. This isn't legal advice.
How hard is it to leave?
Supabase can be self-hosted, which is the usual "no lock-in" argument. The vendor's own self-hosting guide adds the cost. Docker is "the fastest and recommended way", but "Some features of the managed platform aren't available when self-hosting: branching, advanced metrics beyond logs, managed backups and PITR, analytics and vector buckets, ETL, and the Management API". You also take on server provisioning, security hardening, Postgres maintenance, and backups and disaster recovery.
So leaving Supabase Cloud is possible, and it isn't free. Your data is still plain Postgres, though, and that's the real exit.
Firebase's own docs describe no self-hosted production option, and its emulator page warns against using the emulators as "self-hosted" versions of Firebase services. For the rest, we only have a vendor's view. Supabase's comparison page calls Firebase "Tight coupling to Google Cloud products" and describes Supabase as a "Portable architecture; you can move between Supabase Cloud and self-hosted deployments without rewriting your app". Both are marketing claims from the party selling the alternative. Treat them that way, and ask any Firebase team what moving a Firestore document model to tables would take. We'd expect a rewrite of the data layer. That's judgment.
What security setup do you owe before real users?
On Supabase, tables created in the dashboard have row-level security (RLS) on by default, but tables created through the SQL Editor or other tools need it enabled explicitly. The docs are blunt: "A table in an exposed schema without RLS is readable and writable by any role with a grant on it. Enable RLS on every table in an exposed schema." That's from the row-level security guide. If a tool generated your app, locking down row-level security before launch is the step to do first.
On Firebase, access control is Security Rules. Firebase's rules documentation says they "stand between your data and malicious users", apply to Firestore, Realtime Database and Cloud Storage, and Firestore databases created in production mode deny all reads and writes until you write rules. Test mode is open and expires after 30 days. Whichever you pick, schedule an access-rules review before the first real user signs up.
Supabase vs Firebase at a glance
| Feature | Supabase | Firebase |
|---|---|---|
| Database | Postgres | Firestore documents, plus a Cloud SQL for PostgreSQL option (SQL Connect) |
| Entry plan | Free, $0/month, paused after 1 week of inactivity | Spark, no payment method needed |
| Paid plan | Pro from $25/month, spend cap on by default | Blaze, billing account required |
| Billing shape | Tier plus metered overage | Per operation on Firestore |
| EU location | Six named European regions, four in EU member states | Default location is immutable once set; Auth processes data in the US per the privacy page |
| Self-hosting | Yes, with listed missing features | No self-hosted production option documented; emulators are not for production |
| Access control | RLS; on by default for dashboard-created tables, explicit otherwise | Security Rules; production-mode Firestore denies all access by default; test mode is open for 30 days |
Who do you need to hire for each?
This section is judgment. We have no hiring-market figures for either platform.
A Supabase build needs someone who's comfortable in SQL and Postgres: schema design, indexes, migrations, and writing RLS policies that don't leak. Screening for that is covered in screening for SQL and Postgres skills.
A Firebase build suits a front-end or mobile engineer who knows the Firebase SDK and thinks in documents. That engineer can ship a working product quickly. The risk is later: reporting across documents, and a data model shaped by the first screen you built.
The mismatch to avoid is hiring a SQL specialist for a Firestore product, or a front-end generalist to design a relational schema from scratch.
What this means for your MVP backend decision
Start from the database your team can hire for, not from the feature list. That's judgment, and it's the one that holds up when the first engineer leaves.
If your data is relational, or EU residency is on your customers' checklist, Supabase with a named EU region is the safer default. If you're building a real-time, offline-tolerant mobile app with a front-end-heavy team, Firebase fits the work, per the Firestore docs' sync and offline description. Either way, put the access-rules review on the plan before launch, and set the Firebase default location or the Supabase region deliberately, since neither is cheap to change later.
Then ask which vendor's bill grows with your usage in a way you can forecast. Flat tiers and per-operation billing behave differently at scale.
Once the backend is chosen, the next question is who builds on it. Hiring your first engineer as a founder without a technical background walks through it.
FAQ
Is Supabase cheaper than Firebase?
It depends on your usage, and we won't invent a scenario. As of October 2026, Supabase bills a flat tier (Pro from $25/month) plus metered overage, and Firestore bills per document read, write and delete. A chatty app generates more billable reads and writes on Firestore. A data-heavy app tests Supabase's disk and egress limits.
Is Supabase GDPR compliant, and can I keep data in the EU?
You can choose from six European regions, four of them in EU member states, but Supabase's own docs say region selection "is a data-location control, not proof of regulatory compliance". Compliance depends on how you process data and your contracts. Check any region name against the docs, since the general Europe option includes London and Zurich.
Can I move from Firebase to Supabase later?
Yes, but plan it as a data-layer rewrite, not a copy. Firestore documents don't map mechanically onto Postgres tables. Every query changes and access rules get rewritten. We've no sourced cost or time figure for it, so be wary of anyone quoting one.
Is Firebase NoSQL only?
No longer. Firebase's docs describe a relational option backed by Cloud SQL for PostgreSQL, renamed from Firebase Data Connect to Firebase SQL Connect. Firestore, the main database, is still document-based.
Which is easier to hire for?
No source we used measures it. Our judgment: Supabase wants an engineer who knows SQL and Postgres, and Firebase wants a front-end or mobile engineer who knows its SDK. Ask a recruiter for actual candidate numbers in your location and seniority range.