Supabase vs Firebase vs Appwrite: which backend should you build on?

What are Supabase, Firebase and Appwrite?

All three are backend-as-a-service platforms. They give you a database, authentication, file storage, serverless functions and realtime updates behind client SDKs, so a small team can ship an app without building a backend from scratch.

Firebase is Google’s managed platform. Its main databases, Cloud Firestore and the older Realtime Database, are NoSQL document and tree stores, and it is deeply integrated with Google Cloud, analytics and mobile tooling.

Supabase is an open-source platform built around PostgreSQL. You get a real relational database with SQL, row-level security policies, an auto-generated API, auth, storage, edge functions and realtime, either on its cloud or self-hosted.

Appwrite is an open-source backend server you can self-host with Docker or use as a cloud service. It exposes databases, auth, storage, functions and messaging through a consistent API and SDKs for many platforms.

How do they compare side by side?

Why the data model matters most

The most important difference is not features but the database underneath. SaaS products usually have relational data: users belong to organisations, which own projects, which contain tasks with comments. Postgres handles joins, constraints and reporting over that naturally.

Firestore’s document model is excellent for data read in the shape it is stored, such as chat messages or user profiles, and it scales reads with little effort. Relational queries and aggregates need denormalisation, duplicated data and careful planning.

Appwrite presents a document-style API that feels simple from the client, with relationships as a feature on top. It suits apps with modest relational needs where developer ergonomics matter more than advanced SQL.

If you are unsure, sketch your five most important screens and the queries behind them. The shape of those queries usually picks the platform for you.

When is Supabase the right choice?

Supabase fits teams who know SQL or want to learn it, products with reporting needs, and anyone who wants an exit path. Because your data lives in standard Postgres, you can dump it and move to any Postgres host.

Row-level security keeps authorisation next to the data, which is powerful but demands discipline: every table exposed to clients needs correct policies, and mistakes can leak data. Treat policies as code with tests.

For AI features, pgvector lets you store embeddings next to your records, so semantic search can filter by the same tenant and permissions as the rest of your app.

Supabase also leans into developer workflow: a CLI for local development, database migrations in version control, generated TypeScript types and branching for preview environments on its cloud. Teams used to Postgres tooling feel at home quickly.

Its weak point is the flip side of that flexibility. Postgres rewards people who understand indexes, query plans and connection pooling, and a poorly indexed table hurts just as it would on any Postgres host.

When is Firebase the right choice?

Firebase remains a strong choice for mobile apps and rapid prototypes, especially when you also want crash reporting, push notifications, remote config and analytics from one vendor.

Its realtime sync and offline support on mobile clients are mature. For a consumer app where data is mostly per-user and read-heavy, it can take you far with very little backend code.

The cost is lock-in. There is no self-hosted Firebase, security rules and data layouts are specific to it, and migrating a large Firestore dataset to another system is a real project. Pricing follows reads, writes and storage, so inefficient queries translate directly into bills.

Firebase has also added more options over time, including a Postgres-backed offering through Firebase Data Connect and AI features tied to Google’s models. Check which products are generally available in your region before designing around them.

When is Appwrite the right choice?

Appwrite appeals to teams that want open source and self-hosting but prefer a unified API over managing a database directly. Running it with Docker on your own server gives you auth, storage and functions in one package.

Its SDK coverage across web, mobile and server platforms is broad, and the console is approachable for developers new to backends.

The ecosystem is smaller than Firebase or Supabase, so you will find fewer tutorials and third-party integrations. Check that the features you need, such as specific auth providers or query types, exist in the version you plan to run.

A single Appwrite deployment is comparatively easy to reason about, since one project bundles most backend concerns. That makes it a reasonable pick for agencies that host several small client apps on their own servers.

Which should you choose?

• B2B SaaS with organisations, roles and reporting: Supabase.
• Mobile consumer app that needs push, analytics and offline sync fast: Firebase.
• Self-hosted backend with a simple document API and many SDKs: Appwrite.
• Data residency or on-premise requirements: Supabase or Appwrite self-hosted.
• AI features over your own records, such as semantic search: Supabase with pgvector is the most direct path.
• Hackathon or weekend prototype: whichever SDK you already know.

How to choose in five steps

Weight step two heavily. Self-hosting is hard to add later on a platform that does not support it, while a self-hostable platform can always be used as a managed cloud first.

Step four deserves a full day. Write the permission rules for a realistic scenario, such as a member who may read but not edit another member’s project, and try to break them from the client.

• Model your core entities and the queries behind your main screens.
• Decide whether self-hosting or data residency is a requirement now or likely later.
• Estimate read and write volume and compare against each pricing model.
• Prototype authentication and access control first, since that is where platforms differ most.
• Plan your exit: how would you export data and users if you had to leave?

Common mistakes

The most expensive mistake is the one you only discover at scale: a data model that fights the platform. It is far cheaper to spend a day modelling queries now than a month migrating later.

RepoLoot’s catalog lists SaaS starters and self-hosted apps built on each of these backends, a quick way to study real schemas and auth setups.

• Exposing Supabase tables without row-level security policies, or with policies nobody tested.
• Designing Firestore collections like SQL tables, then paying for many small reads.
• Self-hosting any of the three without backups, monitoring and an upgrade plan.
• Putting service or admin keys in client code.
• Choosing on free-tier generosity rather than on how the data model fits your product.

Frequently asked questions

Is Supabase a drop-in Firebase replacement?

No. Supabase is often called an open-source Firebase alternative, but it uses a relational Postgres database rather than documents. Migrating means redesigning your data model and security rules, not swapping SDK calls. For new projects that fits many teams better, but it is a different system.

Can I self-host Firebase?

No. Firebase is a managed Google service. The Firebase Local Emulator Suite runs services locally for development and testing, but it is not meant for production. If self-hosting is a requirement, look at Supabase or Appwrite.

Is self-hosted Supabase hard to run?

It is manageable but not trivial. The self-hosted stack runs several services, including Postgres, an API gateway, auth, storage and realtime, typically via Docker Compose. You own backups, upgrades, secrets and monitoring, so plan for that work.

Which is best for AI apps?

For retrieval over your own data, Supabase is convenient because pgvector keeps embeddings next to records and permissions. Firebase offers vector search and close ties to Google’s AI services. Appwrite works well as the app backend with a separate vector store if needed.