What is the main difference between Supabase and Firebase?

Supabase is a managed Postgres platform with a relational database, row-level security, and a $25/mo Pro plan that includes generous quotas before metering starts. Firebase is Google's NoSQL BaaS built around Firestore's document model with pay-as-you-go Blaze pricing, billed per document read and write, not per GB. The core difference is SQL versus NoSQL, and a larger free allowance versus a smaller one before either platform starts metering usage.

Does Firestore actually bill reads by the gigabyte?

No, and this is one of the most commonly repeated errors in Supabase vs Firebase cost comparisons. Firestore's Blaze plan bills $0.06 per 100,000 document reads and $0.18 per 100,000 writes, a per-operation model, not a per-GB one. Storage itself is billed separately at roughly $0.26 per GB stored. A collection of many small documents can cost far more in read operations than its raw data size would suggest, which a flat per-GB estimate would miss entirely.

When should I choose Firebase over Supabase?

Choose Firebase when you are building a native mobile app and need a decade of battle-tested iOS, Android, and Flutter SDKs. Firebase also wins for offline-first applications where Firestore's client-side caching and conflict resolution are more mature than Supabase's real-time offering. For solo developers with no SQL experience who need to ship fast, Firebase's schema-free document model removes the initial setup friction.

What are the free tiers for Supabase and Firebase?

Supabase's free plan covers up to 2 active projects, 500 MB of Postgres database storage, 1 GB of file storage, 5 GB of egress, and 50,000 monthly active users, but projects pause after 7 days without an API request. Firebase's Spark plan is free with 1 GB of Firestore storage plus daily quotas of 50,000 reads, 20,000 writes, and 20,000 deletes, and it does not pause inactive projects. Neither requires a credit card on the free tier.

Is Supabase's $25/mo Pro plan really a fixed cost?

Not entirely, and treating it as a hard ceiling is the second most common error in this comparison. The Pro plan is $25/mo and includes a $10 compute credit plus generous quotas, 8 GB database storage, 100,000 monthly active users, 100 GB file storage, 500 realtime connections, but usage beyond those quotas is billed per unit, the same metered model Firebase uses. The real difference isn't flat versus metered pricing, it's how much usage each platform includes before metering kicks in, and Supabase's included allowance is substantially larger.

What is the biggest hidden cost trap in Firebase production use?

Firestore's onSnapshot listener charges a document read on the initial snapshot, not only on subsequent changes. A screen subscribing to a 10,000-document collection fires 10,000 read operations every time a user opens the app, even if nothing has changed since their last session. At $0.06 per 100,000 reads, that's a small charge per open, but it compounds fast across many users and frequent reconnects, and there's no way to paginate a real-time listener to reduce the initial snapshot cost.

How hard is it to migrate from Firebase to Supabase?

Migrating from Firebase to Supabase is effectively a rewrite. Firestore's document model does not map to relational tables without redesigning your data architecture, and there is no official migration tooling. Firebase Auth UIDs can be imported but every Firestore collection becomes a manual ETL project. The reverse migration, from Supabase to any other Postgres provider, is a standard pg_dump and restore. This asymmetry in switching cost is significant.

Does Supabase or Firebase perform better at scale?

For relational, join-heavy, or analytical queries, Supabase on Postgres wins because Firestore cannot execute joins at all. For simple document retrieval at global scale with minimal query complexity, Firestore's horizontal scaling and Google's CDN infrastructure offer a real advantage. Supabase's free tier pauses after 7 days of inactivity, causing 10 to 30 second cold starts, which makes it unsuitable for production without at least the $25/mo Pro plan.

How does Supabase real-time compare to Firestore real-time?

Supabase real-time uses Postgres logical replication over WebSockets and delivers only changed rows, billed as part of the same connection-and-message quotas as the rest of the Pro plan rather than a distinct per-read charge. Firestore real-time listeners charge a document read on the initial snapshot when a client subscribes, even if data hasn't changed since the last session. For apps with large collections and frequent client reconnects, that initial-snapshot cost is worth modeling explicitly. Firestore's offline sync and conflict resolution remain more mature for mobile use cases.

Tech Duel

Supabase vs Firebase

Supabase gives you a real Postgres database with SQL and a $25/mo Pro plan that includes generous quotas before metering starts. Firebase gives you Google's NoSQL Firestore, billed per document read and write, not per GB, a distinction most cost comparisons get wrong. The right pick depends on whether your data is relational, how predictable your usage is, and whether you're building mobile-first.

Last reviewed: July 2026

Quick verdict: Supabase vs Firebase

Choose Supabase if your data is relational, your team knows SQL, or you want a large included quota before metering starts rather than Firebase's smaller daily free limits.

Choose Firebase if you're building a native mobile app, your data is naturally document-shaped, or you need mature offline-first sync without managing a schema.

Neither plan is truly flat-rate: both meter usage past their included quotas, they just draw the line in different places.

When to choose Supabase vs Firebase

Choose Supabase when…

Your data is relational and you need joins, foreign keys, or complex queries Firestore can't execute
You're migrating an existing Postgres database, or want to migrate away eventually without lock-in
You want a large included quota (8 GB DB, 100K MAU, 100 GB storage on Pro) before usage-based billing kicks in
You need Postgres-native extensions like pgvector for embeddings or PostGIS for geospatial, without bolting on separate services
Open-source, self-hostable infrastructure matters to you — Supabase runs on Docker under Apache 2.0

Choose Firebase when…

You're building a native mobile app and want a decade of hardened iOS, Android, and Flutter SDKs
Your data is naturally document-shaped and doesn't need relational joins
You need offline-first sync with mature client-side caching and conflict resolution
You're shipping solo and want to skip schema design entirely to start fast
Your traffic is genuinely low and unpredictable — Firebase's free daily quotas don't pause the way Supabase's free tier does

That's the generic picture. Whether your data is relational and how predictable your usage is are what usually tip it. ↓

Supabase vs Firebase: at a glance

Dimension	Supabase	Firebase
Data model	Relational (Postgres)	Document (Firestore)
Joins	Native SQL joins	Not supported
Pricing model	$25/mo Pro, includes quotas, then metered overage	Free Spark, or metered Blaze pay-as-you-go, no flat tier
Free tier	500 MB DB, 1 GB storage, 5 GB egress, 50K MAU, 2 active projects	1 GB storage, 50K reads / 20K writes / 20K deletes per day
Free tier pause	Yes, after 7 days with no API request	No pause
Pro/paid included quota	8 GB DB, 100K MAU, 100 GB storage, 500 realtime connections for $25/mo	None — Blaze meters from the first unit past the free daily quota
Read/write billing unit	Included in Pro quota, then metered per unit	Per document: $0.06/100K reads, $0.18/100K writes
Storage cost past free tier	Usage-based past 8 GB on Pro	~$0.26/GB stored
Self-hosting	Yes, open source (Apache 2.0), Docker	No, proprietary
Mobile SDKs	Growing, web/backend-first	iOS, Android, Flutter — mature, first-party
Vector / geospatial	Native via pgvector, PostGIS	Requires separate services

Supabase vs Firebase: the cost comparison most articles get wrong

A lot of Supabase vs Firebase content, including earlier versions of comparisons like this one, states Firestore bills reads at a per-GB rate. It doesn't. Firestore's Blaze plan bills $0.06 per 100,000 document reads and $0.18 per 100,000 writes, an operation-count model, not a data-volume one. Storage is billed separately at roughly $0.26 per GB. A collection of many small documents can rack up read costs that have nothing to do with how much data those documents actually contain, which a flat per-GB estimate would completely miss.

The second common oversimplification runs the other way: framing Supabase's $25/mo Pro plan as a fixed, predictable cost against Firebase's "unpredictable" metered billing. Pro isn't flat. It includes generous quotas, 8 GB database, 100K monthly active users, 100 GB storage, 500 realtime connections, but usage past those quotas is billed per unit, the same metered structure Firebase uses. The real difference isn't flat-rate versus metered; it's how much usage is included before either platform starts charging by the unit, and Supabase's included allowance is substantially larger than Firebase's free daily quotas.

Where the pricing models diverge in practice is the free tier's behavior under inactivity. Supabase pauses free-tier projects after 7 days without an API request, which means a side project with irregular traffic can face a 10-30 second cold start on its first request back. Firebase's Spark plan doesn't pause, but its free quotas are daily, not monthly, so a spike in traffic on any single day can exhaust the free allowance faster than Supabase's monthly-scoped limits would.

Model your actual read/write volume against both platforms' real billing units before trusting a flat cost comparison from either vendor's marketing page.

Supabase vs Firebase: mobile SDKs and offline support

Firebase's mobile story is close to a decade old at this point, and it shows in the tooling: first-party iOS, Android, and Flutter SDKs, Crashlytics for crash reporting, Remote Config for feature flags, Cloud Messaging for push, and Firestore's offline-first sync with client-side caching and conflict resolution built in. For a mobile-first product, that's a lot of infrastructure you don't have to assemble yourself.

Supabase's mobile SDKs exist and are actively developed, but the platform is still primarily web and backend-first in how its tooling matures. Offline support in particular is thinner: Supabase doesn't ship the same level of built-in client-side caching and conflict resolution Firestore has refined over years of mobile production use. Teams building offline-tolerant mobile apps on Supabase typically build more of that layer themselves.

Worth noting: Firebase's Data Connect, a managed Postgres backend with a GraphQL-like query layer, launched in 2024 as Firebase's first SQL-adjacent offering. It's a genuinely new product, not a replacement for Firestore, and doesn't change the offline/mobile-SDK calculus above, but it's a sign the "Firebase means NoSQL, full stop" framing is getting less accurate over time.

If your product is mobile-first with real offline requirements, weigh that specifically. It's a bigger gap than the general feature list suggests.

Common questions about Supabase vs Firebase

What is the real difference between Supabase and Firebase in 2026?

Supabase gives you a real Postgres database with SQL, row-level security, and a $25/mo Pro plan with generous included quotas before metering starts. Firebase gives you a schema-free NoSQL document store with Google-scale infrastructure and pay-as-you-go billing charged per document read and write, not per GB. The choice is relational versus document model, and a larger included allowance versus a smaller free daily quota. After six months in production, the billing model difference almost always matters more than the database model.

Which is cheaper for a startup: Supabase or Firebase?

For early-stage startups with light traffic, both free tiers are genuinely free. Once you need production reliability, Supabase Pro's $25/mo includes 8 GB database, 100K MAU, and 100 GB storage before overage billing starts — a large included allowance, though not a hard ceiling. Firebase Blaze has no base charge, but read-heavy apps with real-time listeners can generate real costs from Firestore read operations alone. If you can't predict your usage, Supabase's larger included quota gives more room before metering kicks in. If your app has genuinely low and predictable traffic, Firebase Blaze can stay cheaper than $25/mo.

Can I self-host Supabase instead of paying for the managed service?

Yes. Supabase is Apache 2.0 licensed and provides an official Docker setup for self-hosting, with one of the larger followings on GitHub for an open-source project and active daily development. The self-hosted version is production-capable, though you lose managed backups, automatic scaling, and support, and you own the infrastructure completely. Firebase cannot be self-hosted: it's a proprietary Google platform with no open-source equivalent.

Does the Supabase free tier pause projects?

Yes. Supabase pauses free-tier projects after 7 days of inactivity, which means the first request after a pause can take 10 to 30 seconds to respond. This makes the free tier unsuitable for any app with real users, even low-traffic ones. Firebase's Spark free tier does not pause, though its quotas are daily rather than monthly. If you're building a side project with irregular traffic, factor in the $25/mo Pro cost to avoid the pause behavior, or use Firebase.

Which platform is better for a mobile app: Supabase or Firebase?

Firebase is better for native mobile apps. Its iOS, Android, and Flutter SDKs represent a decade of production hardening and are the default choice for mobile developers worldwide. Firebase also offers Crashlytics, Remote Config, Cloud Messaging, and offline-first Firestore sync, none of which Supabase replicates natively. Supabase is catching up with mobile SDKs but is still primarily a web and backend platform. For a mobile-first product, Firebase reduces friction at every layer of the stack.

Does Firebase have a SQL option now?

Yes, as of 2024: Firebase Data Connect is a managed Postgres backend with a GraphQL-like query layer, Firebase's first SQL-adjacent product. It doesn't replace Firestore and isn't a like-for-like substitute for Supabase's Postgres access, but it's evidence the "Firebase is NoSQL-only" framing is getting dated. If you're choosing based purely on data model, check Data Connect's current maturity against your specific requirements rather than assuming Firebase has no SQL path at all.