Firebase vs. Supabase: A Developer’s Honest Comparison

If you’re a mobile developer like me (Android, iOS, Flutter 🙋‍♂️), you know the drill:

You have a killer app idea.
You open your IDE.
And then you hit the wall: The Backend.

And the simpliest solution for this is: “Just use Firebase.” It’s Google’s magic box. You throw JSON at it, and it syncs to everyone’s phone instantly.

But lately, there’s a new challenger on the block: Supabase. It calls itself the “Open Source Firebase Alternative,” and it’s built on top of the mighty PostgreSQL.

So, for my next app (maybe a major update for Buckist?), which one am I picking? Let’s break down the Firebase vs. Supabase battle, just based on my personal needs and experience.

Who's gonna win my choice? Firebase or Supabase?

1. The Database: Firestore (NoSQL) vs. PostgreSQL (SQL)

This is the biggest difference, and it changes how you code entirely.

Firebase (Firestore) is a NoSQL document store. Think of it like a giant, messy folder of JSON files.

The Good: It is incredibly fast to set up. You don’t need to plan your schema.
The Bad: Querying is limited. Want to filter data by “Users who bought shoes AND live in Vietnam AND signed up last week”? Good luck! Also the supported queries are very limited.

Supabase is just PostgreSQL with a nice UI.

The Good: It’s standard SQL. You can use JOINS, foreign keys, and complex filters. If your app has related data (like myMoney has Categories -> Transactions), SQL keeps your data sane.
The Bad: You actually have to design your database schema upfront. Honestly I just put this to compare with Firestore, design database schema first is crucial skill, you should master it anyway.

Verdict: If you need relational data, Supabase wins. If you need unstructured logs, Firebase wins. I faced many problems with Firestore and querying data, so I’ll pick Supabase.

2. Pricing: The “3AM Billing Anxiety”

This is the main reason I’m going to migrate from Firebase to Supabase.

Firebase charges based on Reads and Writes. If you write a bad loop in your code that accidentally reads your database 10,000 times a second, you will wake up to a massive bill. It’s a pay-per-use model that punishes inefficient code. Personal experience: I have to cache database on the client side and limit user interval requests to avoid exceed calls to Firestore - this cause bad experience to users to be honest.

Supabase charges based on Storage Size. They generally don’t care how many times you read the data. If your database fits in 500MB, the price is predictable, whether you have 10 users or 10,000 users.

I do my best just to minimize number of calls to Firestore.

Verdict: I hate to sacrify user experience to save money. Supabase to go.

3. Realtime Capabilities: Magic vs. Sockets

If you are building a chat app, a live score tracker, or a multiplayer game, Firebase is still the king.

Firebase: Realtime is in its DNA. Data updates on the client side in milliseconds with zero configuration.
Supabase: Uses PostgreSQL’s replication log to send updates via WebSockets. It works well, but you have to manually “subscribe” to tables. It feels slightly more “manual” than Firebase’s magic.

Verdict: This should be a tie. Choose based on your need.

4. Vendor Lock-In: Open Source vs. Google

Firebase: It is proprietary. You are locked into the Google Cloud ecosystem. If Google shuts down a feature (which, let’s be honest, Google does often), you are stuck.
Supabase: It is Open Source. You can self-host Supabase on your own server (DigitalOcean, AWS, or a Raspberry Pi) using Docker. You own your data.

Final Verdict: Which Backend Should You Choose in 2025?

After building apps with both, here is my rule of thumb:

Stick with Firebase if:

You are building an MVP or a simple prototype this weekend.
You need the absolute best offline support for mobile apps.
You heavily rely on Google Analytics and Crashlytics.

Switch to Supabase if:

Your app relies on relational data (e.g., Customers, Orders, Inventory).
You are worried about unpredictable billing spikes.
You want the power of SQL to run complex queries without hacking your code.

What I’m Using

For my simple tools, I still love Firebase. But for my more complex personal finance apps like myMoney, I’m finding myself reaching for Supabase. The peace of mind of having a structured SQL database—and a predictable bill—is worth the switch.

What about you? Let me know in the comments!