Supabase vs Firebase
Supabase vs Firebase: Which Backend Should You Build On?
Here is the short answer. Choose Supabase when your data is relational, you want full SQL and row-level security enforced in the database, and you care about self-hosting or the option to leave later: it is open-source Postgres with auth, realtime, and storage built around it. Choose Firebase when you need offline-first mobile sync out of the box, you live in the Google ecosystem, and shipping a working prototype this week matters more than the query model you will live with in year three.
Firestore's built-in offline persistence and mature mobile SDKs are still ahead of anything Supabase ships, and Supabase's relational model and portability are things Firebase cannot retrofit. The rest of this page walks the dimensions buyers actually decide on, then shows how we make the call in real projects. We build and migrate on both platforms, so we do not need either one to win.
At a glance
Supabase vs Firebase at a glance
Nine dimensions buyers actually decide on. Numbers are from each platform's official pricing and docs, checked August 2026.
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Data model
Supabase vs Firebase on data model: Postgres or NoSQL?
Every Supabase project is a full Postgres database. You get tables, foreign keys, constraints, views, and any SQL you can write, including joins and aggregates across the whole schema. Firebase's databases, Firestore and the Realtime Database, are NoSQL document stores: data lives in collections of documents, there are no joins across collections, and relational shapes get denormalized and duplicated by hand.
Firebase has an answer to SQL now: its docs describe SQL Connect, formerly Data Connect, as a relational service backed by Cloud SQL for Postgres and queried through GraphQL. It is a separate product with its own model, not Firestore becoming relational, so an existing Firestore app does not inherit it.
Our take: if your product has users, orders, and invoices that reference each other, it is relational at heart. Start it in Postgres.
Auth
How do Supabase Auth and Firebase Authentication compare?
Both platforms ship first-party auth, and both are good. Firebase Authentication has the broader provider catalog and is free up to 50,000 monthly active users, with phone sign-in billed per SMS. Supabase Auth covers email, OAuth providers, and SSO, includes 50,000 monthly active users on the Free plan and 100,000 on Pro, and stores users in your own Postgres, so you can join auth data against your tables directly.
Our take: auth is close to parity and rarely decides this choice. The database underneath it does.
Security
Row-level security vs Security Rules: who guards the data?
Supabase enforces authorization with Postgres row-level security: policies live in the database and apply to every query path, so a correct policy protects the data even when application code is wrong. The known failure mode is a table shipped with RLS switched off, which the public API key then exposes. Firebase uses Security Rules, a separate language that guards access from client SDKs; server-side code using the Admin SDK bypasses rules entirely, so server endpoints need their own checks.
Our take: RLS is the deeper model but it demands discipline. We ship it on by default, on every table that holds user or tenant data.
Realtime and offline
Which handles realtime and offline better?
Supabase Realtime gives you three primitives: listening to Postgres changes, broadcast messaging between clients, and presence for tracking who is online. Firebase has run realtime listeners at scale for over a decade, and it adds the thing Supabase does not have: offline. Firestore's offline persistence is built in and enabled by default on Android and Apple platforms, caching data locally, queueing writes, and syncing with last-write-wins when the device reconnects.
Supabase ships no built-in offline mode. An offline-first app on Supabase means engineering a local store and a sync layer, with a tool like PowerSync or your own engine.
Our take: offline-first mobile is Firebase's strongest single argument. On Supabase, budget for the sync layer as real scope, not a checkbox.
Pricing
Firebase vs Supabase pricing: metered operations or plan tiers?
Firebase meters usage. The free Spark plan includes, for Firestore, 50,000 reads, 20,000 writes, and 20,000 deletes per day, 1 GiB of storage, and 10 GiB of monthly egress; past that, the Blaze plan bills per operation, per GB stored, and per GB transferred. Costs track traffic closely, which is efficient at low volume and surprising when a chatty screen multiplies reads.
Supabase sells plans. Free covers two active projects with a 500 MB database and 5 GB egress, and pauses a project after a week of inactivity. Pro is $25 per month per organization with 8 GB of database disk and 250 GB of egress included, then $0.09 per GB beyond, with spend caps on by default so overage is opt-in.
Our take: Supabase is easier to forecast. Firebase can be cheaper at low traffic and expensive under read-heavy access patterns, so model your reads before trusting the free tier.
Lock-in and maturity
Self-hosting, lock-in, and ecosystem maturity
Supabase is open source and self-hostable with Docker Compose, and because the core is standard Postgres, leaving the platform is a database dump, not a re-architecture. Supabase's own docs are candid that self-hosting drops managed conveniences like branching, managed backups, and platform metrics, and puts provisioning, hardening, and disaster recovery on you. Firebase is proprietary and runs only on Google's infrastructure; leaving Firestore means re-modeling documents into a new database, which is why Firebase-to-Supabase migrations are a project, not an export.
Maturity cuts the other way. Firebase's mobile tooling, Crashlytics, Analytics, and Cloud Messaging form an ecosystem Supabase does not try to match, and it is battle-tested at enormous scale.
Our take: if the option to leave matters to you at all, this dimension alone can decide the comparison.
The decision
When to choose which
When to choose Supabase
- Your data is relational: SaaS, marketplaces, anything with entities that reference each other
- You want authorization enforced in the database with row-level security, not only in app code
- You need real SQL for reporting, aggregates, or analytics on live product data
- Self-hosting, open source, or a clean exit path is a requirement, not a nice-to-have
- Your team already knows Postgres and wants to keep using it
When to choose Firebase
- Offline-first mobile: built-in persistence, queued writes, and sync on reconnect
- You are validating an idea and want the fastest path to a working prototype
- You are invested in the Google ecosystem: Analytics, Crashlytics, Cloud Messaging
- Your data is genuinely document-shaped and simple, with few cross-entity queries
- Per-operation pricing fits your traffic, and free Spark quotas cover the early stage
Not sure which backend fits your product?
Proof
How we decide in real projects
2muchcoffee is a US company with a senior global team, shipping software since 2015. We have production work on both sides of this comparison, so the recommendation follows the product, not a favorite tool.
An AI-powered mentoring and coaching platform: psychosocial matching, KPI progress tracking, Node.js and Moleculer microservices on Google Cloud with Firestore. Document data, document database, right call.
A full-stack Next.js and Supabase app, deployed and running: Supabase auth and Postgres, typed end to end. Read the code before you talk to us.
Our engineering write-up on the connection-pool exhaustion that hits Vercel and Supabase apps as they grow: how it shows up, how to diagnose it, and the architecture that fixes it.
When a product outgrows Firestore we port schema and data to Postgres, re-express Security Rules as row-level security policies, and migrate auth without forcing password resets. RLS ships on by default on every table that holds user data.
Questions
Supabase vs Firebase, answered
Is Supabase better than Firebase?
Neither is better in the abstract. Supabase is better for relational products: it is real Postgres with full SQL, row-level security, and an open-source exit path. Firebase is better for offline-first mobile apps and fast prototypes: its offline persistence and mobile SDKs are more mature, and its Google-ecosystem integrations are unmatched. Pick by data model and exit requirements, not by popularity.
Is Supabase cheaper than Firebase?
It depends on traffic shape. Supabase sells plan tiers: a free tier, then Pro at $25 per month with 250 GB of egress included and $0.09 per GB beyond, with spend caps on by default, which makes costs easy to forecast. Firebase bills per operation on the Blaze plan after free quotas, so a low-traffic app can cost almost nothing while a read-heavy app can get expensive. Model your reads and egress before trusting either free tier.
Does Firebase support SQL now?
Partly. Firebase docs describe SQL Connect, formerly called Data Connect, as a relational database service backed by Cloud SQL for Postgres and queried through GraphQL with generated typed SDKs. It is a separate product alongside Firestore, not a SQL layer over your existing Firestore data, so adopting it is a data-modeling decision, not a toggle.
Can we migrate from Firebase to Supabase without downtime?
Yes, in phases that keep the app online. We port schema and data from Firestore to Postgres, re-express Firebase Security Rules as Postgres row-level security policies, and migrate authentication without forcing every user to reset a password. You get a migration plan before anything moves.
Which is better for mobile apps, Supabase or Firebase?
For offline-first mobile, Firebase: Firestore caches data locally, queues writes, and syncs on reconnect, enabled by default on Android and Apple platforms. Supabase works well for online mobile apps through its auth and realtime, but it ships no built-in offline mode, so an offline-first app on Supabase needs an engineered sync layer such as PowerSync.
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