Supabase vs Firebase for an MVP: Cost, Lock-in and Security
Both give you a database, sign-in, file storage and real-time updates without running servers. They differ in how data is shaped, how you pay and how hard it is to leave. Here is a fair comparison with the monthly cost worked out, from a studio whose default database is PostgreSQL.
Pick Supabase if your data is relational (organizations, users, roles and invoices that point at each other), you want SQL for reporting, or you want a standard PostgreSQL database you can move later. A production project starts at $25 a month on the Pro plan, with daily backups and 100,000 monthly active users included.
Pick Firebase if you are building a mobile-first app around live sync with simple, document-shaped data, or you already work in Google Cloud. Small apps pay very little: in our worked example, 2,000 monthly active users cost $1.35 a month on Firebase's pay-as-you-go plan. Disclosure: PostgreSQL is our default database, and Supabase is one of the two backend options in our tech stack guide.
What Each One Is
Supabase is a hosted PostgreSQL database with sign-in, file storage, server functions and real-time features around it. PostgreSQL is "a powerful, open source object-relational database system that uses and extends the SQL language." Supabase can also be self-hosted with Docker.
Firebase is Google's app platform. Its main database, Cloud Firestore, is "a NoSQL, document-oriented database." Around it sit Authentication, Cloud Storage, Cloud Functions and Hosting. Firebase also offers SQL Connect (formerly Data Connect), "a fully-managed PostgreSQL database powered by Cloud SQL" with a GraphQL schema, so Firebase is no longer document-only.
Disclosure in full: our rapid MVP tech stack guide names PostgreSQL as our default database and lists Supabase as one of our two backend approaches, next to Node.js. Every outside figure below is sourced, so you can check our fairness.
Supabase vs Firebase: Side-by-Side Comparison
| Factor | Supabase | Firebase |
|---|---|---|
| Database | PostgreSQL: tables, rows and SQL | Cloud Firestore: documents in collections. SQL Connect adds Cloud SQL for PostgreSQL |
| Free plan | $0: 500 MB database, 1 GB of files, 50,000 monthly active users, 2 active projects. Paused after a week of inactivity; no backups | Spark, $0: Firestore 1 GiB stored, 50,000 reads and 20,000 writes a day; 50,000 monthly active users. No Cloud Storage or Cloud Functions |
| Paid plan | Pro from $25 a month: 8 GB database, 100 GB of files, 250 GB egress, 100,000 monthly active users, daily backups kept 7 days | Blaze, pay as you go: the free quotas, then per document read and write, per GB and per user |
| What drives the bill | The plan, plus compute size | Document reads and writes, data sent, sign-ins above 50,000 users a month |
| Spending limit | Spend Cap on Pro blocks usage beyond quota (compute excluded) | Budget alerts "do not cap your usage or charges"; spend caps exist for some services |
| Real-time | Broadcast, Presence and database changes; 500 concurrent connections and 5 million messages on Pro | Real-time listeners, billed one read per document added or updated in the results |
| Access control | Row level security policies inside Postgres | Firebase Security Rules |
| Server code | Edge Functions: 500,000 invocations free, 2 million on Pro | Cloud Functions, Blaze only: 2 million invocations a month free, then $0.40 per million |
| Leaving | Standard Postgres: CLI dump, restore with psql; self-hosting possible | Managed export to Cloud Storage on Blaze; documents reshaped into tables to move to SQL |
Plan figures from the official pricing pages, checked November 2026. Firestore prices are for the Standard edition. See Sources.
Data Model: Tables vs Documents
This is the biggest difference, and it shapes everything else.
PostgreSQL stores data in tables with fixed columns, linked by keys: a user belongs to an organization, an invoice belongs to a customer. You ask questions in SQL and join tables as needed. That suits B2B SaaS, marketplaces and anything with reporting. Our SaaS MVP guide shows the pattern we default to: one database, an organization ID on every customer-owned table, and row level security to keep customers apart.
Firestore stores documents. Its docs: "Unlike a SQL database, there are no tables or rows. Instead, you store data in documents, which are organized into collections." A document can hold its own subcollections. That suits data shaped like your screens: a chat room and its messages, a user profile, a feed. Relational-style joins exist through correlated subqueries, but Firebase documents them for Firestore's Enterprise edition; the free quotas and prices here are for the Standard edition.
A practical test: list your main records and draw how they refer to each other. Many arrows: tables. Mostly standalone records: documents work well.
What a Small MVP Pays Each Month
Supabase charges a flat plan price; Firebase's Blaze plan charges for usage above free daily quotas. So the comparison needs usage numbers.
Our assumptions (not vendor figures, so swap in your own):
- Each monthly active user has 20 sessions a month, and each session reads 150 records and writes 15.
- Usage is spread evenly over a 30-day month, because Firestore's free quota is per day.
- A database under 1 GiB, 4 GB of uploaded files, and 6 GiB a month of data sent from the database at 2,000 users, 60 GiB at 20,000 (about 1 KiB per record read).
- Firestore Standard edition at us-central1 prices: $0.03 per 100,000 reads, $0.09 per 100,000 writes, and $0.12 per GiB sent beyond the free 10 GiB a month.
- Supabase Pro with one project on the Micro compute size, which the plan's $10 of monthly compute credits covers.
Reads: 2,000 users × 20 sessions × 150 = 6,000,000 a month, or 200,000 a day. At 20,000 users it is 60,000,000 a month, or 2,000,000 a day. Writes: 600,000 a month (20,000 a day) and 6,000,000 a month (200,000 a day).
| Monthly item | Firebase, 2,000 users | Firebase, 20,000 users | Supabase Pro, either |
|---|---|---|---|
| Reads | (200,000 − 50,000 free) × 30 = 4,500,000 billable; 45 × $0.03 = $1.35 | (2,000,000 − 50,000) × 30 = 58,500,000; 585 × $0.03 = $17.55 | Included |
| Writes | 20,000 a day, inside the free 20,000: $0 | (200,000 − 20,000) × 30 = 5,400,000; 54 × $0.09 = $4.86 | Included |
| Data sent | 6 GiB, inside the free 10 GiB: $0 | (60 − 10) GiB × $0.12 = $6.00 | Included up to 250 GB |
| Sign-ins and 4 GB of files | Inside free quotas: $0 | Inside free quotas: $0 | Included |
| Plan | $0 | $0 | $25 |
| Total a month | $1.35 | $17.55 + $4.86 + $6.00 = $28.41 | $25.00 |
Billable reads and writes are divided by 100,000 before the price is applied. Supabase Free would not do here: 4 GB of files is over its 1 GB, free projects pause after a week of inactivity, and it has no backups. Firebase Spark would not either: it does not include Cloud Storage.
What the numbers say:
- At MVP scale, Firebase usually costs less in cash. Its free daily quotas absorb a small app, while Supabase charges $25 from the first production month. The $25 buys a predictable bill and daily backups.
- The gap closes as usage grows. At 20,000 users the two are about level: $28.41 against $25.
- Firebase's bill follows how your screens read data. If each session read 1,500 records instead of 150, say a dashboard that loads a long list, reads at 20,000 users would cost (20,000,000 − 50,000) × 30 = 598,500,000 billable, so 5,985 × $0.03 = $179.55 a month. Supabase does not bill per row read: the extra load counts toward egress and database capacity, and the next compute size up, Small, is about $15 a month, against which the $10 credit applies.
- Sign-ins past 50,000 users a month. Firebase bills them at Google Cloud Identity Platform rates, from $0.0055 per user: 60,000 users would add 10,000 × $0.0055 = $55 a month. Supabase Pro includes 100,000, then charges $0.00325 each.
Auth, File Storage and Real-Time
- Sign-in. Both handle accounts for you and include 50,000 monthly active users at no cost; Supabase Pro raises that to 100,000. On Firebase's free Spark plan, Authentication with Identity Platform is also limited to 3,000 daily active users, and SMS verification codes need the Blaze plan.
- File storage. Supabase includes 1 GB free and 100 GB on Pro, then $0.0213 per GB. Cloud Storage for Firebase "now requires projects to be on the pay-as-you-go Blaze pricing plan"; new buckets get 5 GB stored and 100 GB downloaded a month free in three US regions.
- Real-time. Supabase Realtime covers Broadcast ("send low-latency messages between clients"), Presence ("track and synchronize user state across clients") and Postgres Changes ("listen to database changes in real-time"). Firestore's real-time listeners work with offline persistence in its SDKs, and each document added to or changed in a listener's results is billed as a read.
On our price list, real-time features (live chat, notifications or collaborative updates) are +$2,000 and +3 build days.
Security: Row Level Security vs Security Rules
On both platforms the app in the browser or phone talks to the database directly. That makes them fast to build with, and it means the access rules are the lock on your data.
- Supabase uses row level security (RLS): rules written in SQL inside Postgres that decide which rows each user can see or change. Its docs say to "Enable RLS on every table in an exposed schema," because "a table in an exposed schema without RLS is readable and writable by any role with a grant on it." The mental model: "Think of a policy as adding a WHERE clause to every query."
- Firebase uses Security Rules, a separate rules language. Rules are not filters: "If a query could potentially return documents that the client does not have permission to read, the entire request fails." So queries must be written to match the rules, and rules that look up other documents are billed as reads.
Neither is safer by default. On both, test every rule by signing in as two users from two different customer accounts and checking that neither can see the other's data. Our guide to taking an AI-built prototype to production has a ten-question checklist for this.
Lock-in and Moving Off Later
Leaving Supabase. Your data is in PostgreSQL. Supabase's docs show how to dump roles, schema and data with its CLI and restore them with psql, Postgres's standard client. Self-hosting is possible, with caveats in Supabase's own guides: self-hosted Supabase is "community-supported" and lacks branching, managed backups and point-in-time recovery, and moving a hosted project there means copying storage files and edge functions separately, while users sign in again because the signing keys change.
Leaving Firebase. Firestore's managed export needs the Blaze plan, writes files to a Cloud Storage bucket and costs "one read operation per document exported." Exports can be loaded into BigQuery. Moving to a SQL database means reshaping documents into tables: Supabase's migration guide copies each Firestore collection into one Postgres table, and nested data has to be split into related tables with your own scripts. Its auth guide imports Firebase users using Firebase's password hash parameters.
Three habits keep you free to move either way: keep database calls in one part of the code rather than in every screen, export your data on a schedule, and hold the accounts in your company's name.
What AI App Builders Use
If you prototyped with an AI app builder, the choice may already be made:
- Lovable turns on a built-in backend by default, which its docs say "utilizes Supabase's open-source foundation." You can "connect your own Supabase project when you want direct ownership of the backend."
- Bolt has a built-in Bolt Database. On Pro or Teams plans you can choose Supabase when setting up a new project, and Bolt's docs say there is "no supported way to migrate an existing Bolt database to Supabase."
- Firebase Studio, Google's prototyping environment, sets up Cloud Firestore and Firebase Authentication for apps that need them. But it "is sunsetting on March 22, 2027," and new workspaces have been disabled since June 22, 2026. Apps already deployed to Firebase keep running.
Check which backend your prototype sits on before you plan the next step. What to fix before real users arrive is in Lovable, Bolt or Replit vs hiring a developer.
Decision Framework: When Each Wins
| If this is true | Lean | Why |
|---|---|---|
| Your data has many relationships (organizations, members, roles, invoices) | Supabase | Tables, joins and SQL |
| Customers will want reports or exports | Supabase | SQL answers new questions without reshaping data |
| You want a predictable monthly bill with backups included | Supabase | $25 Pro plan with a Spend Cap and daily backups |
| You may self-host or move to another Postgres host | Supabase | Standard Postgres dump and restore |
| A mobile-first app built around live sync and offline use | Firebase | Real-time listeners with offline persistence |
| Usage is tiny or spiky and $25 a month matters | Firebase | Free daily quotas cover small apps |
| Your team already runs on Google Cloud or knows Firebase | Firebase | Familiar tools beat a migration |
| You want Postgres but inside Firebase | Firebase SQL Connect | Cloud SQL for PostgreSQL, from about $9.37 a month |
Two or more Supabase rows: start with Supabase. Mostly Firebase rows: Firebase will serve you well. If you are also choosing how to build the app itself, see web app, PWA or native app and React Native vs Flutter.
When We Are Not the Right Choice
Our standard stack is PostgreSQL, so if Firestore is clearly the better fit for your product, a team that builds on Firebase every day will serve you better than we will. We are also the wrong hire if you only need a database set up for an app you are building yourself: a few hours with a freelancer costs less than a fixed-scope build. And if your product already runs well on Firebase, do not migrate for its own sake. A working product with users beats a cleaner stack.
We fit when you want the whole MVP built (database, sign-in, payments, admin and deployment) at a fixed price from $5,000, delivered in 30 days or less, with all custom code and full source code yours on full payment. See MVP development for what is included, and our terms for the delivery guarantee.
Not Sure Which Backend Fits?
Book a free call and bring a list of your main records and how they connect. We will tell you which database fits and give you a fixed price for the build.
Book a Free Call →Frequently Asked Questions
Is Supabase cheaper than Firebase?
Not at small scale. Supabase's Pro plan starts at $25 a month, while Firebase's free daily quota covers 50,000 document reads and 20,000 writes, so a small app pays little. In our worked example, 2,000 monthly active users cost $1.35 a month on Firebase and $25 on Supabase Pro. As reads grow, or sign-ins pass 50,000 users a month, Firebase's usage bill can overtake the flat fee.
Can I move from Firebase to Supabase later?
Yes, but plan it as a migration project, not an export button. Supabase's guide copies each Firestore collection into one Postgres table, and nested data has to be split into related tables with your own scripts. Its auth guide imports Firebase users using Firebase's password hash parameters. Firestore's managed export needs the paid Blaze plan and charges one read per document exported.
Does Supabase use PostgreSQL?
Yes. Each Supabase project is a hosted PostgreSQL database with sign-in, file storage, edge functions and real-time features around it. You can query it with SQL, protect it with row level security policies, and dump it with the Supabase CLI and restore it with psql. Supabase can also be self-hosted with Docker, although its docs say self-hosting is community-supported and lacks managed backups.
Which is more secure, Supabase or Firebase?
Neither by default. Both let your app read the database directly, so security depends on the access rules you write. Supabase uses Postgres row level security, and its docs say a table in an exposed schema without it is readable and writable by any role with a grant on it. Firebase uses Security Rules. On both, test every rule with two users from two different customer accounts.
What do Lovable and Bolt use for the backend?
Lovable turns on a built-in backend by default that its docs say uses Supabase's open-source foundation, and you can connect your own Supabase project instead. Bolt has a built-in Bolt Database, and on Pro or Teams plans you can choose Supabase when setting up a new project. Google's Firebase Studio sets up Firestore and Firebase Authentication, but it is sunsetting on March 22, 2027.
Is Firebase free for an MVP?
Often at first, with a catch. The free Spark plan excludes Cloud Storage and Cloud Functions, so an MVP with file uploads or server code needs the pay-as-you-go Blaze plan and a payment method. Blaze keeps the free quotas, so a small app may still pay very little. Firebase's budget alerts do not cap charges, so watch screens that read many documents.
Sources
All pages checked November 2026. Cloud prices change often and vary by region; check the official pages and calculators before you budget.
- Supabase, Pricing (Free and Pro quotas, $25 Pro plan, backups, pausing, overage prices, Realtime and Edge Function quotas): supabase.com/pricing
- Supabase Docs, Manage Compute usage (Micro about $10, Small about $15 a month, $10 compute credits): supabase.com/docs/guides/platform/manage-your-usage/compute
- Supabase Docs, Spend cap (Pro plan, excluded items): supabase.com/docs/guides/platform/spend-cap
- Supabase Docs, Row Level Security: supabase.com/docs/guides/database/postgres/row-level-security
- Supabase Docs, Realtime (Broadcast, Presence, Postgres Changes): supabase.com/docs/guides/realtime
- Supabase Docs, Self-Hosting (Docker, community support, missing features): supabase.com/docs/guides/self-hosting
- Supabase Docs, Restore a Platform Project to Self-Hosted (storage, edge functions, sign-in after keys change): supabase.com/docs/guides/self-hosting/restore-from-platform
- Supabase Docs, Backup and Restore using the CLI: supabase.com/docs/guides/platform/migrating-within-supabase/backup-restore
- Supabase Docs, Migrate from Firebase Firestore and Migrate from Firebase Auth: supabase.com/docs/guides/platform/migrating-to-supabase/firestore-data and supabase.com/docs/guides/platform/migrating-to-supabase/firebase-auth
- PostgreSQL, About: postgresql.org/about
- Firebase, Pricing (Spark and Blaze quotas, Authentication, Cloud Storage, Cloud Functions, SQL Connect from about $9.37 a month): firebase.google.com/pricing
- Firebase Docs, Firebase pricing plans (Spark and Blaze, budget alerts do not cap charges): firebase.google.com/docs/projects/billing/firebase-pricing-plans
- Google Cloud, Firestore pricing (us-central1 reads, writes, deletes, network egress, how listeners and rules are billed): cloud.google.com/firestore/pricing
- Firebase Docs, Cloud Firestore data model: firebase.google.com/docs/firestore/data-model
- Firebase Docs, Perform joins with subqueries (Enterprise edition): firebase.google.com/docs/firestore/pipelines/perform-joins-with-sub-pipelines
- Firebase Docs, Securely query data (rules are not filters): firebase.google.com/docs/firestore/security/rules-query
- Firebase Docs, Export and import data (Blaze plan, Cloud Storage bucket, one read per document, BigQuery): firebase.google.com/docs/firestore/manage-data/export-import
- Firebase Docs, Default bucket and billing requirements for Cloud Storage for Firebase (Blaze plan required): firebase.google.com/docs/storage/faqs-storage-changes-announced-sept-2024
- Firebase Docs, Firebase Authentication limits (3,000 daily active users on Spark with Identity Platform, SMS on Blaze only): firebase.google.com/docs/auth/limits
- Google Cloud, Identity Platform pricing ($0.0055 per monthly active user from 50,000 to 100,000): cloud.google.com/identity-platform/pricing
- Firebase Docs, Firebase SQL Connect (formerly Data Connect; Cloud SQL for PostgreSQL, GraphQL schema): firebase.google.com/docs/sql-connect
- Firebase Docs, Firebase Studio (App Prototyping agent sets up Firestore and Authentication; sunsetting March 22, 2027): firebase.google.com/docs/studio
- Lovable Docs, Supabase integration (built-in backend on by default, connecting your own Supabase project): docs.lovable.dev/integrations/supabase
- Bolt Support, Bolt Database (choosing Supabase on Pro or Teams, migration limits): support.bolt.new/cloud/database
- minidev.pro, Rapid MVP tech stack guide (PostgreSQL default, Supabase as a backend option): minidev.pro/blog/tech-stack-rapid-mvp-development-2026
- minidev.pro, MVP cost calculator price list: minidev.pro/mvp-cost-calculator
- minidev.pro, Terms of service (delivery guarantee, IP on full payment): minidev.pro/terms