Supabase vs Firebase (2026): Pricing, Lock-In, Which to Pick

Legacies is an independent digital product and software studio based in Bucharest, Romania, founded by Horia Stan and Alexandru Tălnaci. We build web apps and MVPs with Next.js for founders and small teams around the world, and we have shipped and fixed apps on both Supabase and Firebase.

The short answer: pick Supabase if your data is relational (users, teams, orders, invoices), if you want SQL, or if you want the option to leave later. Pick Firebase if you are building a mobile-first app with offline sync and real-time updates, and you are happy to stay inside Google Cloud. On price, both are cheap at the start. Supabase stays predictable. Firebase is usage-based and harder to forecast.

Quick answer

• SaaS, dashboards, marketplaces, anything with joins and reports: Supabase. Postgres makes this data simple, and the Pro plan is a flat $25/month to start.
• Mobile app with offline mode and live sync: Firebase. Its mobile SDKs and offline cache are more mature.
• App built with Lovable, Bolt or a similar AI builder: usually Supabase already. The real question is whether the security rules are right, not which backend you have.
• Worried about lock-in: Supabase. It is open source, you can self-host it, and your data is standard Postgres.

The real difference: data model, not features

Most comparisons list features side by side. Both products have auth, a database, file storage, server functions and real-time updates. The difference that matters is the database underneath.

Supabase gives you a full PostgreSQL database. You get tables, foreign keys, joins, transactions, views and the whole SQL ecosystem. Add-ons like pgvector for AI embeddings live in the same database as your users and orders.

Firebase is built around Cloud Firestore, a NoSQL document store. Data lives in collections of JSON-like documents. Reads are very fast and the data syncs to clients in real time, but there are no joins. You duplicate data across documents and keep the copies in sync yourself.

Here is what that means in practice. Say you need "all unpaid invoices from customers in Germany, grouped by month." In Postgres that is one query. In Firestore you plan it ahead: you denormalize the country onto each invoice, add a composite index, and do the grouping in code or in a Cloud Function. It is doable, but every new report question becomes a data-modeling task.

Side-by-side comparison

Sources: Supabase pricing and Firebase pricing, checked in October 2026.

Pricing in 2026: what you actually pay

Supabase

Supabase has three main plans at the time of writing:

Above the Pro quota you pay $0.125 per GB of database disk, $0.09 per GB of egress and $0.00325 per extra monthly active user. The catch most people miss: the $10 compute credit covers one small project. A second project, such as a staging environment, pays its own compute. If your app outgrows the Micro instance, you upgrade compute separately.

Never launch a paying product on the Free plan. A project that pauses after a quiet week is fine for a prototype and bad for a business.

Firebase

Firebase has two plans. Spark is free with hard limits. Blaze is pay as you go. On Blaze you still get the free quota, and then you pay per use. For Firestore the free quota is 50,000 reads, 20,000 writes and 20,000 deletes per day, plus 1 GiB stored. Above that, Google Cloud prices apply. In a US single region that has been around $0.06 per 100,000 reads and $0.18 per 100,000 writes at the time of writing. Rates vary by region.

Cloud Functions need Blaze. They include 2 million invocations per month, then $0.40 per million. Phone auth is billed per SMS, also Blaze only.

A worked example

Take a B2B tool with 10,000 monthly active users. Each user opens about 50 screens a month, and each screen reads 20 documents. That is 10 million reads a month.

• Firebase: about 1.5 million reads are free (50,000 a day). The other 8.5 million cost roughly $5. Add writes, storage and functions, and a lean app can stay under $20/month.
• Supabase: Pro at $25/month covers this comfortably on the included Micro compute, as long as queries are indexed.

So at small scale Firebase can be cheaper. The risk is the shape of the curve. Firestore bills per document read, so one badly written real-time listener, or a list screen that reloads 500 documents on every visit, multiplies the bill without any traffic growth. We have seen this pattern in apps generated by AI tools. And Firebase states it plainly: budget alerts do not pause services. Spend caps exist only for a few products, such as Cloud Functions and App Hosting, not for Firestore reads.

Supabase costs grow mostly with database size, egress and compute. A slow query makes the app slow before it makes the bill large, which is easier to notice and fix.

Lock-in and leaving later

This is the point founders underrate the most.

Supabase is open source. Your data is plain Postgres, so pg_dump gives you everything, and any Postgres host can run it. Auth users live in a regular schema. If you outgrow the hosted plan, you can self-host it or move the database to another Postgres provider and keep most of the app.

Firebase runs only on Google Cloud. You can export Firestore data and Auth users, but the app code is written against Firestore's document model and SDKs. Leaving usually means rewriting the data layer and the queries, not just moving the data.

If your product might raise money, get acquired, or face enterprise security reviews, "it is standard Postgres" is a short and easy answer to give.

Security: where both go wrong

Both platforms let the browser or mobile app talk to the database directly. That is what makes them fast to build with. It also means the security rules are your whole backend security. When they are wrong, anyone with your public API key can read or change data.

• Supabase: tables are protected by Row Level Security. If RLS is off on a table, or a policy is too broad, the data is public. This exact mistake was behind the 2025 wave of exposed apps built with AI builders, which we covered in vibe coding security risks.
• Firebase: Security Rules decide who reads and writes each path. The classic failure is a project still in "test mode" with rules that allow everything until a date, or allow read, write: if request.auth != null, which lets every logged-in user read every other user's data.

Neither backend is safer by default. What matters is whether someone checked the rules before launch. Our vibe coded app to production checklist has the full list we run.

1. List every table or collection, and write next to it who should read it and who should write it.
2. Supabase: confirm RLS is enabled on every table in the public schema, then read each policy. Firebase: open the Rules tab and remove any test-mode or catch-all rule.
3. Log in as a second test user and try to load the first user's data with the public key. If it works, you have a leak.
4. Keep the service role key (Supabase) or admin SDK credentials (Firebase) on the server only, never in the frontend bundle.

Which one fits your project

With Next.js on the frontend, which is what we use for most web apps, Supabase fits well. Server components can query Postgres directly, and you get typed results. Firebase works fine with Next.js too, but the client-SDK-first style of most Firebase code fits mobile better than server-rendered web apps.

Hosting is a separate decision. If you are also choosing where to run the frontend, our Vercel vs self-hosting Next.js cost breakdown covers that side.

When the backend choice is not the real problem

Most founders who ask us "Supabase or Firebase?" already have an app. Often it was generated by an AI tool, and something feels off. Bills climb, a query is slow, or nobody is sure the data is private. In those cases switching backends rarely helps. The fix is a proper data model, correct security rules, indexes and a real deploy pipeline.

This is the work our small senior team does. We build custom web apps and MVPs with Next.js, starting at 3,499 lei (about €700), with a fixed price in writing before we start. You can see the packages and the process on our services page. If you are still at the idea stage, how to build an MVP in 2026 and how much it costs to build an app will help you scope it first.

Do it yourself, or hand it over

Doing it yourself is fine when:

• the app is a prototype or internal tool with no sensitive data
• you can read SQL policies or Firebase rules and test them as a second user
• one person owns billing alerts and checks the usage dashboard weekly

Hand it to someone when:

• real customers will store personal or payment data in it
• the bill grows faster than your user count
• you need reports, roles or integrations that the current data model fights against
• you plan to raise money and want the stack to survive a technical review

Look at what we have built, or tell us about your app and get a fixed quote within 48 hours. If you already have a live marketing site, run it through our free website audit first. It checks speed, mobile, basic SEO and accessibility in a few seconds.

Frequently Asked Questions

Is Supabase better than Firebase in 2026?

Neither is better overall. Supabase is the better choice for relational data, SQL, AI features with pgvector and avoiding lock-in, because it is open-source Postgres. Firebase is the better choice for mobile apps that need offline sync and real-time updates, and for teams already on Google Cloud.

Is Supabase cheaper than Firebase?

At very small scale Firebase can be cheaper, because its free quota resets daily and Blaze charges only for what you use. Supabase is more predictable: Pro starts at $25/month with generous quotas and a spend cap on by default. Firebase bills per document read, so inefficient queries can raise costs without any growth in users.

Can I set a spending limit on Firebase?

Only partly. Firebase budget alerts send notifications but do not pause services. Spend caps that pause a service exist only for a few products, such as Cloud Functions, App Hosting, Extensions and AI Logic. Firestore reads are not capped, so you need alerts, efficient queries and regular checks of the usage dashboard.

Can I migrate from Firebase to Supabase?

Yes, but plan for more than a data copy. Supabase provides migration tools for Firebase Auth users and Firestore data. The bigger job is converting nested documents into relational tables and rewriting the app's queries and security rules. For a small app it takes days, and for a large one, weeks.

Which is better for an MVP, Supabase or Firebase?

For most web MVPs, especially SaaS, marketplaces and B2B tools, we recommend Supabase, because the data model stays flexible as the product changes and you can leave later. For a mobile-first MVP built around live sync or chat, Firebase gets you there faster.

Is Supabase safe for production apps?

Yes, if Row Level Security is enabled on every table and the policies are tested. Most Supabase data leaks come from tables with RLS turned off or policies that are too broad, often in apps generated by AI builders. The same applies to Firebase with loose Security Rules.

Can I self-host Supabase or Firebase?

You can self-host Supabase, because it is open source and runs with Docker on your own server. Firebase cannot be self-hosted. It runs only on Google Cloud, though local emulators exist for development and testing.