Supabase vs Firebase for Solo Developers

Quick Comparison

By the Numbers (2026)

I pulled these figures from each vendor's own pricing pages, the public registries, and GitHub on 2026-05-29, so they reflect what you would actually sign up for today rather than what a blog said two years ago.

Adoption and momentum. The Supabase client, @supabase/supabase-js, is on version 2.106.2 and pulled 19,829,221 npm downloads in the week of 2026-05-22 to 2026-05-28. The firebase package sits at version 12.14.0 with 7,231,499 downloads in the same week. On GitHub the main supabase/supabase repository has 103,192 stars and 12,575 forks (first commit October 2019), while firebase/firebase-js-sdk shows 5,122 stars and 1,015 forks (April 2017). Firebase's true reach is wider than that SDK star count suggests because much of its install base is Android and iOS native rather than JavaScript, so read the npm number as the web-and-Node slice of each ecosystem, not the whole platform.

Supabase free tier. Zero dollars gets you 50,000 monthly active users for auth, a 500 MB Postgres database on shared CPU with 500 MB RAM, 1 GB of file storage, 5 GB of egress, and 500,000 Edge Function invocations.

Supabase Pro. A flat $25 per month raises that to 100,000 included MAU (then $0.00325 per extra MAU), 8 GB of database ($0.125 per additional GB), 100 GB of storage ($0.0213 per additional GB), 250 GB of egress ($0.09 per additional GB), and 2 million Edge Function calls (then $2 per additional million). The next step up, Team, jumps to $599 per month.

Firebase Spark (free). No payment method required. Cloud Firestore gives you 50,000 document reads, 20,000 writes, and 20,000 deletes per day, plus 1 GiB of stored data and 10 GiB of outbound transfer per month. Authentication is free up to 50,000 MAU. The catch is the daily reset on Firestore operations rather than a monthly bucket, so a single busy day can hit a wall the free Supabase tier would not.

Firebase Blaze (pay-as-you-go). Once you flip to Blaze you get a one-time $300 credit, then Firestore meters at roughly $0.06 per 100,000 reads, $0.18 per 100,000 writes, $0.02 per 100,000 deletes, and about $0.18 per GiB-month of storage, per the Firebase pricing page. Those exact per-operation rates vary by region and Firestore edition, so check current pricing for your specific region before you forecast a bill. Authentication stays free up to 50,000 MAU on Blaze as well.

Supabase Overview

Supabase is an open-source Firebase alternative built on PostgreSQL. It gives you a real relational database, auth, file storage, edge functions, real-time subscriptions, and auto-generated REST and GraphQL APIs. All from a single dashboard with a generous free tier.

I'm biased toward Supabase because it gives you a real database. Not a document store, not a proprietary query language. Actual PostgreSQL with SQL, joins, foreign keys, and the entire extension ecosystem. You can write complex queries, use PostGIS for geospatial data, or add full-text search. If you outgrow Supabase, you can export your database and run it anywhere. Try doing that with Firestore.

The auth system supports 50,000 monthly active users for free. The storage handles file uploads with transformations. Row-level security lets you define access rules at the database level. For a solo developer, Supabase replaces what would normally be three or four separate services.

Firebase Overview

Firebase is Google's app development platform. It's been around since 2014 and has the maturity to prove it. Firestore (the NoSQL database) syncs data in real-time across clients. Authentication supports every provider you can think of. Cloud Functions handle serverless backend logic. And the free tier is genuinely generous.

Firebase's real strength is speed of development. You can go from zero to a working app with auth, database, and hosting in under an hour. The SDKs are excellent, especially for mobile (iOS, Android, Flutter). Real-time sync is built into the DNA of Firestore, so building collaborative or chat features is remarkably simple.

I've used Firebase for a couple of smaller projects and the onboarding is the best in the industry. The console is clean, the documentation is thorough, and the integration with other Google services (Analytics, Cloud Messaging, Remote Config) is seamless.

Key Differences

SQL vs NoSQL is the fundamental divide. Supabase gives you PostgreSQL with relational data, joins, and proper constraints. Firebase gives you Firestore, a document/collection model with no joins. If your data has relationships (users have posts, posts have comments, comments have authors), PostgreSQL handles this naturally. Firestore requires denormalization and data duplication, which adds complexity as your app grows.

Pricing predictability. Supabase charges a flat $25/month for Pro. You know exactly what you'll pay. Firebase charges per read, write, and storage operation. I've heard multiple stories of developers waking up to unexpected Firebase bills because a poorly optimized query triggered millions of reads. For a solo developer watching every dollar, Supabase's predictable pricing is safer.

Vendor lock-in. Supabase is open source. You can self-host it, export your PostgreSQL database, and move to any other Postgres host. Firebase is proprietary Google infrastructure. If you want to leave, you're rewriting your data layer. This matters when you're building a product you plan to maintain for years.

Real-time capabilities. Firebase has the edge here. Real-time sync is Firestore's core feature and it works flawlessly. Supabase has real-time subscriptions via Postgres changes, but it's not as seamless or battle-tested as Firebase's real-time engine.

Mobile development. Firebase has better mobile SDKs with offline support, push notifications, and analytics. Supabase has Flutter and mobile SDKs, but Firebase's mobile story is more mature after years of development.

When to Choose Supabase

• You want a real relational database you can query with SQL
• You need predictable pricing without per-operation costs
• You value the ability to self-host or migrate away later
• You're building a web application with complex data relationships
• You want auth, storage, and database from one open-source platform

When to Choose Firebase

• You're building a mobile app (iOS, Android, or Flutter)
• Real-time data sync is a core feature of your app
• You want the fastest possible setup and onboarding experience
• You're already in the Google Cloud ecosystem
• You need push notifications and mobile analytics built in

The Verdict

For solo web developers, Supabase is the better choice. The 10/10 rating isn't hype. A real PostgreSQL database with auth, storage, and APIs on a generous free tier is the best deal in developer tools right now. You get a proper database that scales, predictable pricing, and no vendor lock-in.

Firebase wins for mobile-first projects where real-time sync and push notifications are essential. If you're building an iOS or Android app, Firebase's mobile SDKs and offline support are still ahead. But for web applications, SaaS products, and most of what solo developers build, Supabase is the move. I'd rather have PostgreSQL and sleep well knowing I can leave whenever I want.

Real Cost at Solo-Dev Scale

The interesting question is not the sticker price, it is what happens when a small project actually gets some traffic. So let me model one concrete workload and run it through both pricing pages.

Say you have a modestly active app: 10,000 monthly active users, 5 GB of stored data, and on the database side roughly 5 million reads and 1 million writes per month (about 167,000 reads and 33,000 writes per day, which is normal for a feed-style app where people scroll a lot more than they post).

Supabase. This sits comfortably inside the Pro plan. 10,000 MAU is well under the 100,000 included, 5 GB of database is under the 8 GB included, and Supabase does not charge per read or write at all, so query volume is irrelevant to the bill. Total: a flat $25 per month. If you stayed under the free-tier limits (50,000 MAU, 500 MB database), it would be $0, but 5 GB of data pushes you to Pro.

Firebase. Authentication is free at 10,000 MAU, since that is under the 50,000 free ceiling. The cost lives in Firestore. After the free daily quota of 50,000 reads and 20,000 writes per day, you are paying for roughly 3.5 million billable reads (5M minus about 1.5M free per month) and roughly 400,000 billable writes (1M minus about 600,000 free per month). At the Firebase pricing page rates that is about 3.5M reads times $0.06 per 100K, which is about $2.10, plus 400K writes times $0.18 per 100K, which is about $0.72, plus 5 GiB of storage at about $0.18 per GiB-month, which is about $0.90. Total: roughly $4 per month before egress, and Blaze's $300 starting credit would cover months of that.

So at this exact workload Firebase is cheaper, and that is the honest result. The flip happens with read volume, because Supabase does not meter reads. Take the same app and make it read-heavy, say 60 million reads per month (a live dashboard or a chat app polling constantly). Supabase is still a flat $25 because it does not count reads. Firebase now bills roughly 58.5 million billable reads times $0.06 per 100K, which is about $35 per month just for reads, and that number keeps climbing with every additional scroll. The Supabase line stays flat while the Firebase line keeps a slope.

That is the real trade. Firebase wins the small, write-light, low-read project on raw dollars. Supabase wins predictability and wins outright the moment your read volume scales, which for most apps it eventually does. Note these Firestore per-operation rates vary by region and edition, so plug your own region's numbers into the same arithmetic before committing.

Sources

• Supabase pricing (Free, Pro, Team tiers, MAU, database, storage, egress, Edge Function limits and overage rates), https://supabase.com/pricing, checked 2026-05-29
• Firebase pricing (Spark and Blaze plans, Firestore free quotas and Blaze rates, Auth MAU, $300 credit), https://firebase.google.com/pricing, checked 2026-05-29
• Cloud Firestore billing (free daily quota of 50,000 reads, 20,000 writes, 20,000 deletes, 1 GiB storage, 10 GiB monthly egress), https://firebase.google.com/docs/firestore/pricing, checked 2026-05-29
• Firestore per-region and per-edition pricing (rates vary by region), https://cloud.google.com/firestore/pricing, checked 2026-05-29
• @supabase/supabase-js version 2.106.2 (npm registry metadata), https://registry.npmjs.org/@supabase/supabase-js/latest, checked 2026-05-29
• @supabase/supabase-js weekly downloads 19,829,221 for 2026-05-22 to 2026-05-28, https://api.npmjs.org/downloads/point/last-week/@supabase/supabase-js, checked 2026-05-29
• firebase version 12.14.0 (npm registry metadata), https://registry.npmjs.org/firebase/latest, checked 2026-05-29
• firebase weekly downloads 7,231,499 for 2026-05-22 to 2026-05-28, https://api.npmjs.org/downloads/point/last-week/firebase, checked 2026-05-29
• supabase/supabase GitHub stars 103,192 and forks 12,575, https://api.github.com/repos/supabase/supabase, checked 2026-05-29
• firebase/firebase-js-sdk GitHub stars 5,122 and forks 1,015, https://api.github.com/repos/firebase/firebase-js-sdk, checked 2026-05-29