Supabase vs Firebase vs Appwrite: Which BaaS Fits Your Side Project?

You’ve got a weekend free, an idea you can’t shake, and no desire to build authentication, a database schema, and file storage from scratch. That’s exactly the gap backend-as-a-service (BaaS) platforms fill. The three names you’ll hit first are Firebase, Supabase, and Appwrite—and the choice matters more than it looks, because migrating a live app off a BaaS later is a genuine headache.

Here’s a practical comparison aimed at side projects: what each platform is, where it shines, and where it will cost you time or money.

The Short Version

  • Firebase is the most mature option, backed by Google, with the widest feature set. It’s also the most opinionated and the easiest to get locked into.
  • Supabase is an open-source layer on top of PostgreSQL. If you know SQL, it feels like home, and you can self-host or walk away with your data.
  • Appwrite is open source, self-hostable, and designed to be a clean all-in-one backend you run yourself or in the cloud. It’s the newest of the three and iterating fast.

Firebase: The Default Choice, With Trade-offs

Firebase has been around since 2011 (Google acquired it in 2014), and that longevity shows. Authentication, Firestore, Realtime Database, Cloud Storage, Cloud Functions, Hosting, and analytics all live under one roof with solid SDKs for every major platform.

For a side project, the free Spark plan is generous enough to prototype almost anything. Firestore’s real-time sync is genuinely excellent for chat, collaborative tools, or anything where multiple users see the same data update live.

The catch is the data model. Firestore is a document store, which means denormalized data, composite indexes, and security rules written in a custom syntax. If your app is relational at heart—users, posts, comments, tags—you’ll spend real time working around the model instead of with it. Firestore also bills per read/write operation, and costs can climb faster than expected once real users show up. Google’s pricing has changed more than once, so check current rates before you commit.

Lock-in is the other concern. Firestore data doesn’t export into a tidy relational format, and Cloud Functions tie you to Google’s runtime. For a throwaway prototype that’s fine. For something you hope to grow, plan for it.

Supabase: Postgres With Batteries Included

Supabase launched in 2020 and has become the default recommendation for developers who want a real database. Under the hood it’s PostgreSQL—the same database you’d reach for in a traditional stack—wrapped with auto-generated REST and GraphQL APIs, row-level security, auth, storage, edge functions, and real-time subscriptions.

The practical benefit is that your knowledge transfers. SQL is SQL. Row-level security policies are powerful once you understand them, and you can inspect everything through the Supabase dashboard or connect with any Postgres client. The free tier includes two projects and a reasonable database size, which covers most side projects indefinitely.

Supabase is also open source and self-hostable, and it’s built so you can export your data and leave. That’s a meaningful hedge for a project you might eventually take seriously.

The rough edges: row-level security has a learning curve, and a misconfigured policy can silently expose data or block legitimate requests. Real-time is good but less battle-tested than Firestore’s. And while the free tier is generous, paused projects on inactive free accounts can be annoying if you return to a project after months away.

Appwrite: Open Source and Self-Hostable First

Appwrite is the youngest of the three, but it’s carved out a clear niche: a fully open-source backend you can run on your own server with a single Docker command. It bundles authentication, databases, storage, functions, messaging, and more into one consistent API across platforms.

The self-hosting story is Appwrite’s biggest draw. If you already pay for a VPS, you can run Appwrite for the cost of the server—no per-operation billing, no vendor deciding your free tier. The cloud version exists too, with a free tier, if you’d rather not manage infrastructure.

Appwrite’s database is document-oriented like Firestore, so it inherits some of the same modeling trade-offs. Its ecosystem and community are smaller than Firebase’s or Supabase’s, which means fewer Stack Overflow answers when you hit an edge case. But the documentation is solid, and the team ships updates frequently. For a side project where you want full control and predictable costs, it’s a strong contender.

How They Compare on What Matters for Side Projects

Pricing and Free Tiers

All three have free tiers that cover hobby-scale usage. Firebase’s free tier is metered by operations, so a viral moment can produce a surprise bill—set budget alerts regardless. Supabase’s free tier is project-based with database size limits and pauses inactive projects. Appwrite Cloud’s free tier is similar in spirit, and self-hosting makes costs fully predictable. For a side project, none of these will bankrupt you, but Firebase requires the most vigilance.

Learning Curve

If you already know SQL, Supabase is the fastest to productive. If you know JavaScript and want the shortest path to a working real-time app, Firebase’s SDKs are hard to beat. Appwrite sits in between—its API is clean and consistent, but you’ll rely more on official docs than community answers.

Data Portability and Lock-in

Supabase wins here: it’s Postgres, it’s open source, and export is straightforward. Appwrite is also open source and self-hostable, so you can take the whole stack with you. Firebase is the most locked-in, particularly around Firestore and Cloud Functions.

Real-Time and Offline Support

Firebase’s Firestore remains the gold standard for real-time sync and offline persistence, especially on mobile. Supabase real-time is capable and improving. Appwrite supports real-time via its Realtime API but has a smaller track record.

A Simple Decision Framework

  • Choose Firebase if you’re building a mobile app, want real-time sync out of the box, and value the largest ecosystem and documentation base over data portability.
  • Choose Supabase if your data is relational, you know or want to learn SQL, and you care about being able to leave with your data intact.
  • Choose Appwrite if you want to self-host, prefer predictable costs, and like the idea of one consistent open-source backend for web and mobile.

None of these is a wrong answer for a side project. The wrong move is picking one without understanding what leaving would cost.

The Takeaway

For most side projects in 2024 and beyond, Supabase is the safest default: a real Postgres database, a generous free tier, and no lock-in. Firebase remains the better pick when real-time mobile sync is central to the idea. Appwrite is the right call when self-hosting and cost control matter more than ecosystem size. Pick based on your data model and how much you care about portability—then spend your weekend building the product, not the backend.