Supabase vs Firebase vs Appwrite: BaaS 2026

TL;DR

Supabase is the default choice for most teams in 2026 — Postgres-based, open source, excellent TypeScript SDK, and the best developer experience of the three. Firebase (Firestore) remains the go-to for mobile-first apps needing Google's global CDN and offline sync. Appwrite is the right choice if self-hosting is a requirement or you want a fully open source BaaS without vendor lock-in.

The BaaS decision is more consequential than most tool choices because migrating away from one is expensive. Choosing Firebase for a web application that grows to need complex relational queries is a painful refactor. Choosing Supabase for a mobile app that needs offline-first sync requires building what Firestore provides natively. Getting the initial choice right based on your application's data characteristics and deployment requirements saves months of future migration work.

In 2026, Supabase has won the general-purpose web app backend competition. Its combination of SQL power, open source transparency, escape hatch portability, and first-class Next.js integration has made it the standard recommendation. Firebase remains essential for its offline-first mobile capabilities — a use case Supabase doesn't address well. Appwrite is the niche leader for self-hosted, compliance-constrained deployments where data sovereignty is non-negotiable.

Key Takeaways

• Supabase: ~3.2M weekly npm downloads — Postgres + Row Level Security + realtime + storage + edge functions
• Firebase: ~3.7M weekly npm downloads — Google-backed, NoSQL (Firestore), best offline mobile support
• Appwrite: ~180K weekly npm downloads — 100% open source, self-hostable, Docker-based
• Supabase won the "open source Firebase" competition convincingly in 2024-2026
• Vendor lock-in: Firebase is highest (proprietary NoSQL), Supabase is medium (Postgres is portable), Appwrite is lowest (self-hostable)
• All three offer authentication, storage, and serverless functions alongside their database

---

The BaaS Landscape in 2026

Backend-as-a-service platforms let you skip the boilerplate: authentication, database, file storage, and serverless functions in one package. The three main choices have very different philosophies:

Platform	Database	Host Model	Open Source	Self-Host
Supabase	Postgres	Managed cloud	MIT	Docker
Firebase	Firestore (NoSQL)	Google Cloud only	No	No
Appwrite	MariaDB (internal)	Managed cloud	Apache 2	Docker

---

Supabase

Supabase is a Postgres-based BaaS with a clean TypeScript SDK, Row Level Security for authorization, and a thriving ecosystem.

Database + Row Level Security

import { createClient } from "@supabase/supabase-js"

const supabase = createClient(
  process.env.NEXT_PUBLIC_SUPABASE_URL!,
  process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!
)

// Typed queries via auto-generated types:
type Package = {
  id: string
  name: string
  weekly_downloads: number
  created_at: string
}

// SELECT with filter:
const { data, error } = await supabase
  .from("packages")
  .select("id, name, weekly_downloads")
  .gt("weekly_downloads", 1000000)
  .order("weekly_downloads", { ascending: false })
  .limit(10)

// INSERT:
const { data: newPkg, error: insertError } = await supabase
  .from("packages")
  .insert({ name: "react", weekly_downloads: 25000000 })
  .select()
  .single()

// UPDATE:
await supabase
  .from("packages")
  .update({ weekly_downloads: 26000000 })
  .eq("name", "react")

// DELETE:
await supabase.from("packages").delete().eq("id", pkg.id)

Row Level Security (RLS) — the Supabase superpower:

-- Enable RLS on the table:
ALTER TABLE packages ENABLE ROW LEVEL SECURITY;

-- Policy: users can only see their own watchlist:
CREATE POLICY "Users see own watchlist"
ON watchlist
FOR SELECT
USING (auth.uid() = user_id);

-- Policy: public packages visible to all:
CREATE POLICY "Public packages are viewable by everyone"
ON packages
FOR SELECT
USING (is_public = true);

RLS moves authorization logic into the database — the anon key only sees what the policies allow, even on direct API calls.

Authentication

// Email/password signup:
const { data, error } = await supabase.auth.signUp({
  email: "user@example.com",
  password: "secure-password",
})

// OAuth (GitHub, Google, etc.):
await supabase.auth.signInWithOAuth({
  provider: "github",
  options: { redirectTo: "https://app.example.com/auth/callback" },
})

// Get current session:
const { data: { session } } = await supabase.auth.getSession()
const user = session?.user  // { id, email, ... }

// Server-side (Next.js App Router):
import { createServerClient } from "@supabase/ssr"
import { cookies } from "next/headers"

const supabase = createServerClient(
  process.env.NEXT_PUBLIC_SUPABASE_URL!,
  process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!,
  { cookies: { getAll: () => cookies().getAll() } }
)

const { data: { user } } = await supabase.auth.getUser()

Realtime

// Subscribe to table changes:
const channel = supabase
  .channel("packages-changes")
  .on(
    "postgres_changes",
    { event: "INSERT", schema: "public", table: "packages" },
    (payload) => console.log("New package:", payload.new)
  )
  .on(
    "postgres_changes",
    { event: "UPDATE", schema: "public", table: "packages" },
    (payload) => console.log("Updated:", payload.new)
  )
  .subscribe()

// Cleanup:
supabase.removeChannel(channel)

Storage

// Upload file:
const { data, error } = await supabase.storage
  .from("avatars")
  .upload(`${userId}/avatar.png`, file, {
    upsert: true,
    contentType: "image/png",
  })

// Get public URL:
const { data: { publicUrl } } = supabase.storage
  .from("avatars")
  .getPublicUrl(`${userId}/avatar.png`)

// Signed URL (private bucket):
const { data: { signedUrl } } = await supabase.storage
  .from("private-docs")
  .createSignedUrl("report.pdf", 3600)  // 1 hour expiry

Supabase Edge Functions:

// supabase/functions/send-notification/index.ts
import { serve } from "https://deno.land/std@0.177.0/http/server.ts"
import { createClient } from "https://esm.sh/@supabase/supabase-js@2"

serve(async (req) => {
  const { packageName } = await req.json()

  const supabase = createClient(
    Deno.env.get("SUPABASE_URL")!,
    Deno.env.get("SUPABASE_SERVICE_ROLE_KEY")!
  )

  // Deno-based edge functions with full Supabase access
  const { data } = await supabase
    .from("subscribers")
    .select("email")
    .eq("package_name", packageName)

  // Send notifications...
  return new Response(JSON.stringify({ sent: data?.length }))
})

Supabase Edge Functions run on Deno Deploy's infrastructure. The Deno runtime is distinct from Node.js — standard Node.js npm packages don't work directly, and you use Deno-compatible imports. The Supabase team provides a compatibility layer for common packages, and most packages with browser-compatible builds work via esm.sh imports. For teams with complex server-side logic that depends on Node.js APIs, the edge function runtime is a consideration — backend logic that requires native modules or complex Node.js packages should run in a traditional serverless function rather than a Supabase Edge Function.

The Supabase CLI is excellent for local development. Running supabase start spins up a full local Supabase stack — Postgres, auth, storage, edge functions — in Docker, giving you a production-identical development environment. Database migrations are managed with supabase migration commands, and supabase gen types typescript regenerates TypeScript types whenever the schema changes. This local-first development workflow reduces "works on my machine" issues and makes schema changes testable before deployment.

---

Firebase (Firestore)

Firebase is Google's BaaS — the most mature platform but with a proprietary NoSQL data model and no self-hosting option.

Firestore Data Model

Firestore uses a document/collection model — different from Supabase's relational Postgres:

import { initializeApp } from "firebase/app"
import {
  getFirestore,
  collection,
  doc,
  getDoc,
  getDocs,
  setDoc,
  addDoc,
  updateDoc,
  deleteDoc,
  query,
  where,
  orderBy,
  limit,
  onSnapshot,
} from "firebase/firestore"

const app = initializeApp({
  apiKey: process.env.NEXT_PUBLIC_FIREBASE_API_KEY,
  authDomain: "myapp.firebaseapp.com",
  projectId: "myapp",
})

const db = getFirestore(app)

// Documents live in collections, not tables:
// packages/{packageId}
// users/{userId}/watchlist/{packageId}  (subcollection)

// Read a document:
const docRef = doc(db, "packages", "react")
const docSnap = await getDoc(docRef)
if (docSnap.exists()) {
  console.log(docSnap.data())  // { name: "react", downloads: 25000000 }
}

// Query a collection:
const q = query(
  collection(db, "packages"),
  where("weeklyDownloads", ">", 1000000),
  orderBy("weeklyDownloads", "desc"),
  limit(10)
)
const querySnapshot = await getDocs(q)
querySnapshot.forEach((doc) => console.log(doc.id, doc.data()))

// Write a document:
await setDoc(doc(db, "packages", "react"), {
  name: "react",
  weeklyDownloads: 25000000,
  updatedAt: new Date(),
})

// Real-time listener:
const unsubscribe = onSnapshot(
  query(collection(db, "packages"), where("featured", "==", true)),
  (snapshot) => {
    snapshot.docChanges().forEach((change) => {
      if (change.type === "added") console.log("Added:", change.doc.data())
      if (change.type === "modified") console.log("Modified:", change.doc.data())
      if (change.type === "removed") console.log("Removed:", change.doc.data())
    })
  }
)

Firebase Authentication

import {
  getAuth,
  signInWithEmailAndPassword,
  createUserWithEmailAndPassword,
  signInWithPopup,
  GoogleAuthProvider,
  onAuthStateChanged,
} from "firebase/auth"

const auth = getAuth(app)

// Email/password:
await createUserWithEmailAndPassword(auth, "user@example.com", "password")
await signInWithEmailAndPassword(auth, "user@example.com", "password")

// Google OAuth:
const provider = new GoogleAuthProvider()
await signInWithPopup(auth, provider)

// Auth state listener:
onAuthStateChanged(auth, (user) => {
  if (user) {
    console.log("Logged in:", user.uid, user.email)
  } else {
    console.log("Logged out")
  }
})

Firestore Security Rules

Firebase's equivalent of Supabase RLS — document-level access control:

// firestore.rules
rules_version = '2';
service cloud.firestore {
  match /databases/{database}/documents {
    // Users can only read/write their own data:
    match /users/{userId}/{document=**} {
      allow read, write: if request.auth != null && request.auth.uid == userId;
    }

    // Packages are publicly readable:
    match /packages/{packageId} {
      allow read: if true;
      allow write: if request.auth != null && get(/databases/$(database)/documents/users/$(request.auth.uid)).data.isAdmin == true;
    }
  }
}

Firebase strengths:

• Best offline-first mobile support (Firestore's local cache + sync)
• Google's global infrastructure — fastest cold starts anywhere
• Firebase Auth has most OAuth providers out of the box
• Firebase App Check for mobile app integrity
• 10 years of production battle-testing

Firebase limitations:

• Firestore's NoSQL model requires denormalization for complex queries
• No SQL — JOINs, aggregations, and complex filtering are cumbersome
• Vendor lock-in: migrating away from Firestore is painful
• Security rules become complex for sophisticated access patterns
• Pricing is unpredictable at scale (per-read/write pricing)

---

Appwrite

Appwrite is a fully open source BaaS — you can run it on your own infrastructure with Docker, or use Appwrite Cloud.

import { Client, Account, Databases, Storage, Query } from "appwrite"

const client = new Client()
  .setEndpoint("https://cloud.appwrite.io/v1")  // or your self-hosted endpoint
  .setProject(process.env.NEXT_PUBLIC_APPWRITE_PROJECT_ID!)

const account = new Account(client)
const databases = new Databases(client)
const storage = new Storage(client)

// Authentication:
await account.create("user-id", "user@example.com", "password", "Display Name")
const session = await account.createEmailPasswordSession("user@example.com", "password")

// Get current user:
const user = await account.get()

// Database queries:
const documents = await databases.listDocuments(
  "database-id",
  "packages-collection-id",
  [
    Query.greaterThan("weeklyDownloads", 1000000),
    Query.orderDesc("weeklyDownloads"),
    Query.limit(10),
  ]
)

// Create a document:
const doc = await databases.createDocument(
  "database-id",
  "packages-collection-id",
  "unique()",  // auto-generate ID
  {
    name: "react",
    weeklyDownloads: 25000000,
    version: "18.2.0",
  }
)

// File upload:
const file = await storage.createFile(
  "avatars-bucket-id",
  "unique()",
  inputFile,
)

// Get file URL:
const url = storage.getFileView("avatars-bucket-id", file.$id)

Self-hosting Appwrite:

# docker-compose.yml — complete Appwrite stack:
version: "3"
services:
  appwrite:
    image: appwrite/appwrite:1.6
    ports:
      - "80:80"
      - "443:443"
    environment:
      - _APP_ENV=production
      - _APP_OPENSSL_KEY_V1=${APPWRITE_KEY}
      - _APP_REDIS_HOST=appwrite-redis
      - _APP_DB_HOST=appwrite-mariadb
      # ... additional config
  appwrite-redis:
    image: redis:7
  appwrite-mariadb:
    image: mariadb:10.11
    environment:
      MYSQL_ROOT_PASSWORD: ${MARIADB_PASSWORD}

Appwrite's distinguishing features:

• Complete ownership: your data, your server, your infrastructure
• Built-in functions with multiple runtime support (Node.js, Python, PHP, etc.)
• Teams and memberships for multi-tenant apps
• Webhooks for all events
• 100% open source — audit the code, contribute, fork

See also: Best Open-Source Supabase Alternatives on OSSAlt — Looking to self-host? OSSAlt has a full guide to open-source Supabase alternatives.

---

Feature Comparison

Feature	Supabase	Firebase	Appwrite
Database	Postgres	Firestore (NoSQL)	MariaDB (via collections API)
SQL support	Full SQL	No	No (query API only)
Realtime	Postgres changes	Native	Yes
Auth	Excellent	Excellent	Good
Storage	Yes	Yes	Yes
Edge/functions	Yes (Deno)	Yes (Cloud Functions)	Yes (multiple runtimes)
Self-hosting	Yes (Docker)	No	Yes (Docker)
Open source	Yes (MIT)	No	Yes (Apache 2)
TypeScript SDK	Excellent	Good	Good
Offline support	Limited	Excellent	Limited
Free tier	2 projects, 500MB DB	Spark plan (generous)	1 project, 75K requests
Vendor lock-in	Low (Postgres)	High	None (self-host)

---

Database Model: The Key Differentiator

This is the most important choice. The database model shapes your entire data architecture, and switching later is painful. Choosing between relational (Postgres) and document-oriented (Firestore) affects how you model relationships, write queries, and scale reads.

Why relational matters for most web apps: The majority of SaaS applications have relational data. Users have many orders. Orders have many line items. Products belong to categories. These relationships are natural to model with foreign keys, JOINs, and constraints in Postgres. Attempting to model the same data in Firestore requires denormalization — duplicating data across documents to avoid expensive multi-document reads. This denormalization creates synchronization complexity: when a user updates their profile, you need to update the profile data stored in every document that duplicated it.

When NoSQL wins: Document databases excel at content with variable structure, high-volume event streams, and data that is genuinely hierarchical without cross-document relationships. A social media app where each post is a document containing its metadata, media URLs, and interaction counts without relating to other documents is a natural fit for Firestore. The offline-first sync is uniquely valuable for mobile applications where users have unreliable connectivity.

Supabase (Postgres):

-- Full relational model — JOINs, aggregations, CTEs
SELECT
  p.name,
  p.weekly_downloads,
  COUNT(w.user_id) as watcher_count,
  AVG(r.rating) as avg_rating
FROM packages p
LEFT JOIN watchlists w ON w.package_id = p.id
LEFT JOIN reviews r ON r.package_id = p.id
WHERE p.weekly_downloads > 1000000
GROUP BY p.id
ORDER BY watcher_count DESC;

Firebase (Firestore):

// Can't JOIN — must denormalize:
// packages/{id}: { name, downloads, watcherCount, avgRating }  ← computed at write time
// Must update watcherCount whenever someone adds to watchlist (transaction or Cloud Function)

Appwrite:

// Collection-based — no JOINs:
const packages = await databases.listDocuments(
  dbId, "packages",
  [Query.greaterThan("weeklyDownloads", 1000000)]
)
// Relationships require multiple queries or denormalization

The database model choice also determines your long-term data portability. Postgres data can be exported as standard SQL, imported into any Postgres-compatible database (Neon, PlanetScale, AWS RDS, Railway), and queried with any standard SQL tool. Firestore data requires Firebase's proprietary export format and cannot be directly imported into a SQL database without transformation. Appwrite uses MariaDB internally but exposes it only through its collection API — direct SQL access is not supported.

For teams building applications where data analysis is important — business intelligence, analytics dashboards, ad-hoc queries — Supabase's Postgres gives you direct SQL access for data exploration that Firestore and Appwrite don't provide. Analysts can connect Metabase, Redash, or Mode directly to your Supabase database using standard PostgreSQL drivers and run complex aggregation queries without any ETL pipeline.

Row Level Security (RLS) is Supabase's most distinctive feature. By defining Postgres policies on your tables, you can enforce data access rules at the database level rather than in application code. When the anon key is used (client-side requests), only rows allowed by RLS policies are visible. This means even if there's a bug in your application code that accidentally queries the wrong data, the database itself prevents unauthorized data exposure. For applications with sensitive user data, RLS provides a defense-in-depth that neither Firebase Security Rules nor Appwrite's permission system fully replicates.

The performance characteristics also differ. Postgres query planning optimizes complex JOINs automatically — the database query planner chooses the most efficient execution path based on table statistics. Firestore reads are fast for document-level access but expensive for cross-collection queries. Appwrite's query API provides basic filtering and sorting but cannot optimize across collections the way Postgres can optimize across tables.

---

Ecosystem and Community

Supabase has built the most vibrant third-party ecosystem of the three. The supabase-js SDK has deep integration with virtually every JavaScript framework — Next.js has official Supabase documentation, Remix has community adapters, and SvelteKit works out of the box with @supabase/ssr. The Supabase GitHub organization has 50+ repositories covering migrations, CLI, studio, and platform-specific libraries. The Discord community has over 75,000 members and an active #help channel. StackOverflow has thousands of Supabase-tagged questions, and the answers are usually current with the latest SDK.

Firebase's ecosystem reflects its decade of production maturity. The Firebase documentation is extensive, polished, and covers every edge case. The AngularFire, ReactFire, and VueFire community libraries bring framework-native reactive bindings. For mobile development, the Flutter, iOS, and Android Firebase SDKs are best-in-class. Google's backing means the documentation is always maintained, and deprecations are communicated with long runway. The Stack Overflow corpus for Firebase is enormous.

Appwrite's community is younger and growing. The Discord has active contributors and the Appwrite team is highly responsive. The third-party ecosystem is catching up — there are adapters for SvelteKit, SolidJS, and Vue. The key differentiator is that Appwrite's open source license means you can file issues and contribute directly. Community PRs get reviewed and merged, creating a collaborative development dynamic different from Firebase's closed-source model.

Real-World Adoption

Supabase powers thousands of startups and side projects, and has been adopted by teams at companies like Mozilla, Pika, and Humata. The pattern most common in 2026 is using Supabase as the primary database backend for Next.js SaaS applications, replacing combinations of Prisma + separate auth + separate storage. The supabase gen types typescript command generates TypeScript types from your schema, giving end-to-end type safety from SQL schema to React component.

Firebase retains dominant usage in mobile apps built with Flutter or React Native. The offline sync capability — where Firestore persists data locally and syncs when connectivity returns — has no practical equivalent in Supabase for mobile. Companies building consumer apps with complex offline requirements (task managers, notes apps, fitness trackers) frequently stay on Firestore because the tradeoff is clear.

Appwrite is seeing growing adoption in regulated industries (healthcare, government, finance) where data sovereignty requirements make cloud-only providers non-starters. A company processing medical records in Germany, for example, may need to run all infrastructure within specific geographic boundaries — Appwrite's Docker deployment makes this trivial.

Migration Considerations

Migrating from Firebase to Supabase is feasible but requires rethinking the data model. Firestore's denormalized collections need to be restructured into normalized Postgres tables. The Firebase community has documented migration patterns extensively, and tools like firestore-to-supabase help automate data export. Authentication migration is simpler — both platforms support the same OAuth providers, and Supabase can import Firebase Auth users via the Admin API.

Migrating from Supabase to Appwrite is more straightforward since both use SQL-style data models internally. The main differences are the SDK API surface and the absence of Row Level Security in Appwrite (which uses permission-based collections instead).

Final Verdict 2026

For new web applications with relational data — and that's the vast majority of SaaS products — Supabase is the right choice. It gives you the full power of Postgres with the convenience of a managed backend platform, first-class Next.js support, and an escape hatch: if you ever need to migrate off Supabase, your data is in standard Postgres and your schema is portable. The combination of Row Level Security for authorization, realtime subscriptions from Postgres changes, and Deno edge functions makes Supabase a complete backend platform.

Firebase remains the right choice for mobile-first applications with offline-first requirements and for teams deeply embedded in the Google/Android ecosystem. Its decade of production hardening, global infrastructure, and Firebase App Check for mobile integrity are hard to replicate.

Appwrite belongs in any environment where data sovereignty, full self-hosting, and open-source licensing are non-negotiable requirements.

See also: Best SaaS Boilerplates with Supabase on StarterPick — Ready to build? StarterPick lists the best Supabase boilerplates.

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When to Use Each

Choose Supabase if:

• You're building a relational data model (most web apps)
• You want Postgres features: JOINs, CTEs, full-text search, PostGIS
• TypeScript-first with generated types from your schema
• You want open source with managed hosting and an escape hatch

Choose Firebase if:

• Building a mobile-first app needing offline-first sync
• Your data model is document-based (social feeds, chat, IoT events)
• Google's global infrastructure and Firebase Auth's breadth matter
• You're comfortable with NoSQL denormalization patterns

Choose Appwrite if:

• Full data sovereignty — you run it on your servers
• GDPR/compliance requirements mandate on-premises
• You want to avoid vendor lock-in entirely
• Multi-runtime serverless functions (Python, PHP alongside Node.js)

Pricing and Cost Structures

Pricing is a critical consideration when choosing a BaaS platform, and the three have very different cost structures.

Supabase's free tier is generous: 2 active projects, 500MB database, 1GB file storage, 50,000 monthly active users for auth, and 500K edge function invocations. The $25/month Pro plan increases these limits substantially (8GB database, 100GB storage) and removes project pausing. For a production SaaS with moderate traffic, Supabase Pro is often the only paid tier needed for the first year or two. The predictable flat pricing is a major advantage over Firebase's per-operation model.

Firebase's pricing is event-based: document reads, writes, and deletes are each charged separately. The Spark (free) plan includes 50,000 reads, 20,000 writes, and 20,000 deletes per day. At scale, this pricing is unpredictable — a viral moment that causes thousands of concurrent users to read a document collection can generate unexpected bills. Teams at Firebase scale typically use caching strategies and denormalization patterns specifically to minimize read/write costs.

Appwrite Cloud's pricing is comparable to Supabase's flat model. Self-hosting eliminates the cloud cost entirely — you pay only for your own server infrastructure. For organizations that can self-host on existing infrastructure, Appwrite's total cost of ownership is zero beyond server costs, which is unmatched.

Authentication Comparison

All three platforms include authentication — email/password, magic links, and major OAuth providers (Google, GitHub, Apple, Facebook). The differences are in depth and edge cases.

Supabase Auth (formerly GoTrue) has excellent Next.js integration via @supabase/ssr. The server-side session handling, middleware integration, and cookie management are well-documented and actively maintained. Supabase Auth also supports multi-factor authentication, phone OTP, and SAML for enterprise SSO. The generated TypeScript types include auth types, giving you type-safe access to user metadata.

Firebase Auth has the broadest OAuth provider support of the three — over 20 identity providers including Microsoft, Apple, Twitter, GitHub, Yahoo, and game platforms. The Firebase Auth SDK has deep mobile integrations (iOS, Android, Flutter) and supports biometric authentication via Firebase App Check. For applications where auth provider coverage breadth matters — platforms that need to support every possible sign-in method — Firebase Auth's catalog is unmatched.

Appwrite Auth supports 30+ OAuth providers and includes team/membership management that the others lack. The teams API enables multi-tenant architectures where users belong to organizations with role-based permissions, making Appwrite suitable for B2B SaaS without building custom team management.

The Supabase Ecosystem in 2026

Supabase has built the most vibrant third-party ecosystem of the three. The supabase-js SDK integrates with virtually every JavaScript framework — Next.js has official Supabase documentation, Remix has community adapters, and SvelteKit works out of the box with @supabase/ssr. The supabase gen types typescript command generates TypeScript types from your schema, giving end-to-end type safety from database schema to React component.

For teams building Next.js applications in 2026, Supabase is the most commonly paired backend platform. The combination of Row Level Security for authorization, realtime subscriptions from Postgres changes, and Deno edge functions makes Supabase a complete backend. For Next.js auth integration details, the best Next.js auth solutions 2026 comparison covers how Supabase Auth compares to Clerk, NextAuth, and other auth providers.

The escape hatch is also real: if you outgrow Supabase's hosted offering, your data is in standard Postgres. Migrating to a self-hosted Postgres on AWS, PlanetScale, or Neon is straightforward because your schema and queries are standard SQL. This portability is fundamentally different from Firebase, where migrating away requires rethinking your entire data model.

For teams evaluating realtime capabilities, best realtime libraries 2026 covers the socket infrastructure options that complement or replace BaaS realtime for high-scale use cases.

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Methodology

npm download data from npm registry (February 2026). Feature comparison based on Supabase SDK v2.x, Firebase JS SDK v10.x, and Appwrite SDK 14.x documentation. Self-hosting characteristics based on official Docker setup guides.

Cost Analysis at Scale

Pricing is a critical consideration when choosing a BaaS platform, and the three have very different cost structures.

Supabase's free tier is generous: 2 active projects, 500MB database, 1GB file storage, 50,000 monthly active users for auth, and 500K edge function invocations. The $25/month Pro plan increases these limits substantially (8GB database, 100GB storage) and removes project pausing. For a production SaaS with moderate traffic, Supabase Pro is often the only paid tier needed for the first year or two. The predictable flat pricing is a major advantage over Firebase's per-operation model.

Firebase's pricing is event-based: document reads, writes, and deletes are each charged separately. The Spark (free) plan includes 50,000 reads, 20,000 writes, and 20,000 deletes per day. The Blaze (pay-as-you-go) plan charges $0.06 per 100,000 reads and $0.18 per 100,000 writes. At scale, this pricing is unpredictable — a viral moment that causes thousands of concurrent users to read a document collection can generate unexpected bills. Teams at Firebase scale typically use caching strategies and denormalization patterns specifically to minimize read/write costs.

Appwrite Cloud's pricing is similar to Supabase's: a free tier for development and a Pro plan at $15/month per organization for production. Self-hosting eliminates the cloud cost entirely — you pay only for your own server infrastructure. For organizations that can self-host on existing infrastructure, Appwrite's total cost of ownership can be zero beyond server costs.

Realtime Capabilities Compared

Realtime data sync is one of the most demanding use cases for BaaS platforms, and the three platforms have different architectural approaches.

Supabase's Realtime is built on PostgreSQL's logical replication. When a row is inserted, updated, or deleted, the change flows through Postgres's WAL (write-ahead log) and is broadcast to subscribed clients via WebSockets. This architecture means the subscription API mirrors SQL filtering — you can subscribe to changes on a specific table, filtered by row conditions. The latency from database write to client notification is typically 50-200ms in Supabase's hosted environment.

Firebase's Firestore Realtime is its most battle-tested feature. The offline-first architecture means clients receive updates even when network connectivity is unreliable, with automatic conflict resolution when connectivity resumes. Google's global CDN infrastructure means that realtime updates are delivered with lower latency than most alternatives for clients near Google's POPs. Firestore can handle millions of concurrent connections.

Appwrite's Realtime uses WebSockets with a channel subscription model. The subscription API is similar to Supabase's but with Appwrite's collection-based data model. Appwrite Realtime supports subscriptions to database changes, file changes, and custom events, giving it a broader real-time surface area than just database changes.

Related: Firebase Auth vs AWS Cognito vs Supabase Auth 2026, Best Realtime Libraries 2026, Best JavaScript Testing Frameworks 2026

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