Choose Supabase if your data is relational and you want SQL on Postgres, open-source code and a flat $25/month starting price on Pro. Choose Firebase if you're building a mobile-first app, want Google's app tooling and are comfortable with a document database and pay-as-you-go pricing. Both free plans are generous for testing, but they work differently: Supabase pauses free projects after a week of inactivity, while Firebase's Spark plan has daily usage limits and doesn't require a payment method.
The real decision is your data model, and everything else follows from it. Switching later usually means rewriting your data layer, so this is worth getting right at the start. Facts below come from each vendor's own pricing pages and documentation.
Supabase vs Firebase at a glance
| Supabase | Firebase | |
|---|---|---|
| Main database | Postgres (SQL) | Firestore (document database) |
| SQL option | Yes, by default | Firebase SQL Connect, on Cloud SQL for PostgreSQL |
| Open source | Yes, Apache-2.0 | No |
| Self-hosting | Yes, with limits | No |
| Free plan | 500 MB database, 50,000 monthly active users, 1 GB file storage | Spark: 1 GiB Firestore storage, 50K reads and 20K writes a day, 50K monthly active users |
| Free-plan catch | Projects pause after 1 week of inactivity; 2 active projects | Daily limits; some products need Blaze |
| Paid entry | Pro from $25/month | Blaze, pay as you go |
| Auth, storage, functions | All included | All included, some on Blaze only |
| Best for | Relational data, SQL, web apps | Mobile apps, document data, Google's tooling |
The main difference: tables or documents
Supabase gives each project a Postgres database. You store data in tables with relationships and query it with SQL. That suits most business apps, where orders belong to customers and customers belong to accounts. Questions like "total revenue per customer last month" are straightforward to answer.
Firebase's main database, Firestore, stores documents in collections. It's flexible and comes with mobile SDKs, but it's designed around how you read data. You often structure data for specific screens, and reports across many collections take more work.
Firebase also now offers SQL Connect, which connects apps to a managed Cloud SQL for PostgreSQL database. So "Firebase means no SQL" is no longer strictly true, but SQL isn't the default path, and it has its own Google Cloud costs.
A quick test: sketch your app's main data on paper. If it's lots of things linked to other things, and you need reports across them, lean towards Supabase. If it's mostly self-contained records that a phone app reads and syncs, Firestore may be a natural fit.
If these terms are new to you, read our guide to backends, databases and auth for non-coders.
Pricing compared
The pricing models are different, and that matters more than any single number.
Supabase uses plans with included usage:
| Plan | Price | Includes |
|---|---|---|
| Free | $0 | 500 MB database, 50,000 monthly active users, 1 GB file storage, 5 GB egress; paused after 1 week of inactivity; 2 active projects |
| Pro | From $25/month | First project included, additional projects from $10/month; 250 GB egress; daily backups kept for 7 days; extra usage billed at published rates |
| Team | From $599/month | Daily backups kept for 14 days, plus team and compliance features |
| Enterprise | Custom | Custom terms |
Firebase uses a free plan and then metered usage:
| Plan | Price | Includes |
|---|---|---|
| Spark | $0, no payment method needed | 1 GiB Firestore storage, 50K document reads, 20K writes and 20K deletes a day, 10 GiB network egress a month, 50K monthly active users |
| Blaze | Pay as you go | The same no-cost amounts, then usage-based pricing; Cloud Functions include 2M invocations a month at no cost, then $0.40 per million; new accounts may qualify for $300 in credit |
What this means in practice:
- Supabase's bill is easier to predict at the start. You pay a flat $25 and only pay more once you pass the included usage.
- Firebase can cost nothing for a long time and then grow with traffic. It bills per read, write and other operations, so a poorly structured query or a busy feature can raise the bill. Set budget alerts on Blaze.
- Idle projects behave differently. A free Supabase project pauses after a week without activity, while Spark limits are daily and don't pause your project in the same way. For a side project with little traffic, this may decide it for you.
Prices are from each vendor's pricing page in November 2026.
Got an idea? Build it now!
Just start with a simple prompt. No coding required: Greta.sh turns your idea into a working app in minutes.
Features compared
| Feature | Supabase | Firebase |
|---|---|---|
| Authentication | Included | Included; most options are no-cost |
| File storage | Included | Cloud Storage; requires Blaze |
| Functions | Edge Functions | Cloud Functions; requires Blaze |
| Realtime | Broadcast, Presence and Postgres Changes | Firestore real-time listeners |
| Hosting | Not the main focus; pair it with a host | Firebase Hosting and App Hosting |
| Mobile extras | Client libraries | Crashlytics, Cloud Messaging, Remote Config and more |
| Data access rules | Postgres Row Level Security | Firebase Security Rules |
Two practical points:
Security rules matter on both. Each lets client apps talk almost directly to the database, so your access rules are what keep one user out of another's data. A missing Supabase Row Level Security policy or an overly open Firebase rule can expose your data. Test this directly, using our role-based access guide.
Firebase's mobile tooling is its strongest advantage. Crashlytics, Cloud Messaging and Remote Config are useful for a phone app, and Supabase has no direct match for all of them.
Lock-in and leaving
Supabase is built on standard Postgres, so you can export your database and run it on another Postgres host, though you'd still need to replace its auth, storage and functions. It's Apache-2.0 licensed and self-hostable with Docker. Its docs note that a self-hosted install runs as a single project, without branching, managed backups or the Management API.
Firebase is proprietary, and Firestore's data model and security rules don't move directly to another product. Leaving usually means a rewrite of your data layer, which our Firebase alternatives guide discusses.
If neither fits, see our Supabase alternatives for options such as Neon, Convex and Appwrite.
Which should you choose?
| Your situation | Better fit |
|---|---|
| A web app or SaaS with relational data | Supabase |
| You want to write SQL and run reports | Supabase |
| You want an open-source stack you can self-host | Supabase |
| A mobile-first app with push notifications and crash reports | Firebase |
| You're already deep in Google Cloud | Firebase |
| You want a predictable flat price | Supabase Pro |
| A low-traffic project that shouldn't pause | Firebase Spark |
Got an idea? Build it now!
Just start with a simple prompt. No coding required: Greta.sh turns your idea into a working app in minutes.
What if you don't want to manage a backend at all?
Both tools assume someone will set up the schema, access rules and client code. If you want the app without that work, an AI app builder can generate it. Greta.sh builds a full-stack app from a plain-English description and creates its own database for it. It doesn't sit on top of an existing production database, so if you already run Supabase or Firebase with live data, plan for a migration rather than a direct connection.
Database, Flows and GitHub version control are on Pro (a $20/month welcome offer, normally $50/month). Deployment starts on Starter (a $5/month welcome offer, normally $20/month), and the free plan gives you 5 credits a day but cannot deploy. Our piece on why AI app builders need real databases explains why this matters.
FAQ
Is Supabase better than Firebase?
Neither is better in general. Supabase is the better fit for relational data, SQL and open-source requirements. Firebase is the better fit for mobile-first apps that want Google's tooling and a document database. Decide based on your data model.
Is Supabase cheaper than Firebase?
It depends on your usage. Supabase Pro starts at a flat $25/month with included usage, while Firebase charges for what you use after its no-cost limits. A small Firebase app can cost nothing, and a read-heavy one can cost more than Supabase. Estimate from your own traffic.
Is Supabase a replacement for Firebase?
For many apps, yes. It covers a database, authentication, storage, functions and realtime. It doesn't have direct matches for everything in Firebase's mobile tooling, such as Crashlytics, and moving an existing app means restructuring your data from documents into tables.
Does Firebase use SQL?
Firestore doesn't; it's a document database. Firebase SQL Connect is a separate product that connects apps to a managed Cloud SQL for PostgreSQL database.
Is Supabase really free?
It has a free plan with a 500 MB database, 50,000 monthly active users and 1 GB of file storage, limited to 2 active projects. Free projects pause after a week of inactivity, so it's better suited to development than to a live product.
Which is better for a mobile app?
Firebase usually has the edge for mobile because of tools like Crashlytics, Cloud Messaging and Remote Config. Supabase also works well for mobile apps with relational data, and it has client libraries for the common platforms.
Can I use Supabase and Firebase together?
Yes. A common reason would be to keep your data in Supabase and use Firebase for mobile features such as push notifications. It adds complexity and two sets of bills, so only do it if you need something specific from each.
