Firebase or Supabase?

Firebase and Supabase solve the same underlying problem: they give you a ready-made backend so you can build an app without first setting up your own database, login, and servers. But they do it on different foundations, and that difference matters more than most comparisons let on. Here’s where the choice is actually decided.

What the two are

Both are backend-as-a-service (BaaS): database, authentication, file storage, and ready-made APIs packaged as a service. You skip building and operating the server side and can spend your time on the product itself. That’s the big win with both.

Firebase is Google’s established service, built around a NoSQL document database. It’s mature, tightly integrated into Google’s ecosystem, and known for getting an app up and running fast.

Supabase is the open-source challenger, built on the Postgres relational database. It deliberately markets itself as an open alternative and attracts those who want the strengths of a relational database without giving up the convenience of a ready-made backend.

The data model: the choice that actually matters

If you only weigh one thing, weigh this one. Firebase and Supabase differ in the very way they store data, and that shapes the whole system.

Firebase stores documents – entire objects in a NoSQL structure. It’s smooth and fast to get started with, especially when data naturally clumps together. But the same weakness applies as with all document storage: the moment you need to connect data in new ways or ask questions you didn’t prepare for, it gets sluggish.

Supabase gives you a relational database. You get relations, transactions, and free ad-hoc queries from the start – exactly what saves you when reporting and relational needs emerge, which they almost always do. The price is a bit more structure to deal with early on.

The choice between documents and relations, then, isn’t a detail in Firebase-versus-Supabase – it is the question. If your data fits a relational model (and more data does than people think), that weighs heavily toward Supabase.

Lock-in and the path out

This is where the services differ in a way boards and technical leaders should care about.

Firebase is a closed service. Build on it and you become dependent on Google, and moving away later is a real project. Supabase builds on standard Postgres and is open source, meaning you can move it to your own infrastructure if the need arises. That doesn’t mean everyone should self-host – but the option lowers the risk and gives you leverage.

Price curves as the user base grows

Both are cheap or free at small scale. The difference shows up when volume arrives. Firebase bills partly per operation against the database, which can become hard to track and spike under intensive use – a common unpleasant surprise when an app takes off. Supabase sits closer to traditional server rental and is more often predictable as it grows.

Take an app that loads a list every time a user opens a view. On Firebase, each such load can become many billed read operations, and with thousands of active users scrolling heavily, it grows into a line item that surprises. The same pattern on Supabase sits closer to a fixed server cost that doesn’t move as dramatically with the number of clicks. That doesn’t mean one is always cheaper, just that the cost’s shape differs – and an app that’s cheap at a hundred users can behave completely differently at a hundred thousand.

No curve is universally cheapest; it depends on how your specific app reads and writes. The point is to calculate your actual usage pattern early, not to be surprised by the bill after launch.

How to choose

If the app has clearly relational data, and you want to keep the door open to move later, that points toward Supabase. If you’re already deep in Google’s ecosystem and your data fits the document model, Firebase is an equally reasonable choice. Let the data model and the lock-in question weigh the most – not which service feels newest.

Is BaaS even right for you, or is a custom backend needed? That’s the next question, and at Weapp we’re happy to talk it through before you choose a path for the product.