Supabase vs Firebase: Backend Comparison for 2026

Two Philosophies

Supabase and Firebase solve the same problem — giving developers a managed backend so they can ship faster — but they approach it from fundamentally different directions. Firebase is a Google product built on proprietary infrastructure with NoSQL (Firestore) at its core. Supabase is an open-source project built on Postgres with a philosophy of using existing, proven technologies rather than inventing new ones.

This philosophical difference affects everything: data modeling, querying, vendor lock-in, pricing, and the day-to-day experience of building with each platform.

We built a task management application (think a simplified Linear) on both platforms over three weeks. The app includes user authentication, a relational data model with projects, tasks, and comments, file attachments, real-time updates, and role-based access control. These features exercise every major capability of both platforms.

Database

This is the most consequential difference between the two platforms.

Supabase gives you a full Postgres database. You write SQL. You define schemas with foreign keys, indexes, views, and stored procedures. If you know Postgres, you know how to use Supabase's database. The learning curve is the learning curve of SQL itself.

Firebase's Firestore is a document database. Data is stored in collections of documents, each document a JSON-like object. There are no joins. Relationships are modeled through subcollections or document references. Queries are limited compared to SQL — you cannot, for example, filter on two inequality conditions on different fields.

-- Supabase: Get all tasks for a project with assignee details
SELECT
  t.id, t.title, t.status, t.priority,
  u.name AS assignee_name, u.avatar_url
FROM tasks t
LEFT JOIN users u ON t.assignee_id = u.id
WHERE t.project_id = 'proj_123'
ORDER BY t.priority DESC, t.created_at DESC;

// Firebase: Same query requires multiple reads
const tasksSnap = await getDocs(
  query(
    collection(db, 'projects', 'proj_123', 'tasks'),
    orderBy('priority', 'desc')
  )
);
// Now fetch each assignee separately...
const tasks = await Promise.all(
  tasksSnap.docs.map(async (doc) => {
    const data = doc.data();
    const userSnap = await getDoc(
      doc(db, 'users', data.assigneeId)
    );
    return { ...data, assignee: userSnap.data() };
  })
);

For our task management app, the relational nature of the data made Supabase the natural fit. Projects have many tasks, tasks have many comments, users can be assigned to multiple tasks across projects. In Postgres, these relationships are expressed directly. In Firestore, we spent considerable time deciding on data denormalization strategies.

That said, Firestore has genuine strengths. Its offline persistence works out of the box — the SDK caches data locally and syncs when connectivity returns. For mobile applications with intermittent connectivity, this is valuable. Supabase's real-time features require an active connection.

Authentication

Both platforms offer solid authentication with email/password, OAuth providers, and magic links.

In practice, both auth systems work well. Supabase's auth integrates tightly with Postgres Row Level Security (RLS), which means your access control is defined at the database level. Firebase uses Security Rules, a custom DSL that sits in front of Firestore. Both approaches have tradeoffs — RLS is more powerful but requires SQL knowledge; Security Rules are more approachable but less expressive.

We found Supabase's RLS policies easier to reason about for complex access control. Our task app required rules like "team leads can reassign any task in their project, but members can only modify tasks assigned to them." In Supabase, this was a SQL policy. In Firebase, the equivalent Security Rule was verbose and harder to test.

Real-Time

Firebase's real-time capabilities are its strongest feature. Firestore's onSnapshot listeners are reliable, low-latency, and handle offline/online transitions gracefully. The SDK manages connection state, retries, and local cache automatically.

Supabase offers real-time via Postgres's built-in replication. You subscribe to changes on tables, and the Supabase client receives inserts, updates, and deletes as they happen. It works, but it is less mature than Firebase's implementation. During our testing, we encountered occasional delays of 500ms-2s in real-time delivery under load, where Firebase's updates were consistently sub-200ms.

For applications where real-time is the core feature — collaborative editing, chat, live dashboards — Firebase has a meaningful advantage.

Storage

Both platforms provide file storage with access controls. Firebase's Cloud Storage is backed by Google Cloud Storage. Supabase Storage is backed by S3-compatible storage.

Feature-wise, they are comparable. Both support upload, download, presigned URLs, and access policies. Supabase recently added image transformation (resize, crop) on the edge, which is convenient for apps that handle user-uploaded images. Firebase requires integrating with a separate service (like Firebase Extensions for image resizing) to achieve the same result.

Edge Functions and Server-Side Logic

Supabase Edge Functions run on Deno. Firebase offers Cloud Functions on Node.js. Both allow you to run server-side code triggered by HTTP requests, database events, or scheduled timers.

Firebase Cloud Functions are more mature, with a larger ecosystem of triggers (Firestore, Auth, Storage, Pub/Sub, and more). Supabase Edge Functions are newer and currently limited to HTTP triggers and database webhooks.

// Supabase Edge Function (Deno)
Deno.serve(async (req) => {
  const { taskId, status } = await req.json();
  const supabase = createClient(
    Deno.env.get('SUPABASE_URL')!,
    Deno.env.get('SUPABASE_SERVICE_KEY')!
  );
  const { error } = await supabase
    .from('tasks')
    .update({ status, updated_at: new Date().toISOString() })
    .eq('id', taskId);
  return new Response(JSON.stringify({ success: !error }));
});

Pricing

Pricing is where the comparison gets complicated, because the two platforms charge for different things.

Firebase's free tier is more generous on storage and bandwidth. Supabase's free tier gives you a full Postgres database, which is arguably more valuable.

On paid plans, Supabase charges $25/month for the Pro tier with predictable scaling. Firebase's Blaze plan is pay-as-you-go, which can lead to surprise bills. We have heard multiple accounts of developers receiving unexpected Firebase bills when a real-time listener or function goes haywire. Supabase's spending limits on the Pro plan prevent this scenario.

For our test application, estimated monthly costs at 10,000 MAU with moderate data usage:

• Supabase Pro: ~$25-40/month
• Firebase Blaze: ~$15-60/month (high variance depending on read/write patterns)

Developer Experience

Supabase's dashboard is excellent. The table editor, SQL editor, and logs viewer are polished and fast. The documentation is clear and well-organized. The TypeScript SDK generates types from your database schema, which eliminates an entire category of runtime errors.

Firebase's console is functional but showing its age. The Firestore data viewer is slow with large collections. The documentation is comprehensive but scattered across multiple Google properties. The SDK is well-typed but requires more boilerplate.

Both platforms have active communities. Firebase's is larger (it has been around since 2014). Supabase's is growing faster and tends to be more engaged on GitHub and Discord.

Vendor Lock-In

This is Supabase's strongest argument. Your data is in Postgres. If you leave Supabase, you take your database with you — the schema, the data, the stored procedures, all of it. You can run Supabase locally or self-host it entirely.

Firebase's data is in Firestore, a proprietary database. Migration means transforming your data model from documents to whatever your target database uses. This is not impossible, but it is work — and the amount of work scales with the complexity of your data model and the depth of your Security Rules.

Who Should Use What

Choose Supabase if:

• Your data is inherently relational
• You value the ability to write SQL directly
• Vendor lock-in is a concern
• You want predictable pricing
• You plan to self-host eventually

Choose Firebase if:

• Real-time sync is a core requirement
• You are building a mobile app with offline support
• You prefer NoSQL and document-oriented data modeling
• You are already in the Google Cloud ecosystem
• You need mature Cloud Functions with diverse triggers

The Verdict

Supabase is the better choice for most new web applications in 2026. Postgres is a more versatile foundation than Firestore, the developer experience is superior, and the open-source model provides an exit strategy that Firebase cannot match. Firebase remains the better choice for mobile-first applications where real-time sync and offline support are non-negotiable. Both platforms are production-ready and actively improving.

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