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Supabase: Open Source Firebase Alternative with PostgreSQL (2026)

Quick Answer

Supabase is an open-source Backend-as-a-Service built on PostgreSQL. Unlike proprietary BaaS solutions, Supabase uses standard PostgreSQL—meaning your data is portable and never locked in. The platform provides auto-generated REST APIs (via PostgREST), authentication, real-time subscriptions, object storage, and Deno-based Edge Functions. Row Level Security (RLS) enables direct database access from client applications while maintaining data isolation.

What is Supabase?

Supabase positions itself as “PostgreSQL for the cloud-native era.” Rather than building a proprietary database, Supabase wraps standard PostgreSQL with developer-friendly tooling:

  • PostgreSQL Core: Full, isolated instance per project
  • PostgREST: Auto-generated RESTful API from schema
  • GoTrue (Supabase Auth): JWT-based authentication
  • Realtime: Elixir-based WebSocket server for CDC
  • Supavisor: Elixir-based connection pooler for serverless
  • Edge Functions: Deno-based serverless compute

The Architecture

┌─────────────────┐     ┌──────────────┐     ┌─────────────┐
│   Client Apps   │────▶│  PostgREST   │────▶│ PostgreSQL   │
│  (Web/Mobile)   │     │   (REST)     │     │  (with RLS)  │
└─────────────────┘     └──────────────┘     └─────────────┘
      │                       │                      │
      ▼                       ▼                      ▼
┌─────────────────┐     ┌──────────────┐     ┌─────────────┐
│   Supabase      │     │   Realtime   │     │    WAL      │
│     Auth        │     │  (WebSocket) │◀────│ (Replication)│
└─────────────────┘     └──────────────┘     └─────────────┘

Key Features

Row Level Security (RLS)

Supabase’s security model pushes authorization into the database:

-- Enable RLS
ALTER TABLE profiles ENABLE ROW LEVEL SECURITY;

-- Policy: Users can only see their own profile
CREATE POLICY "User can see own profile"
ON profiles
FOR SELECT
USING (auth.uid() = id);

-- Policy: Users can update their own profile
CREATE POLICY "User can update own profile"
ON profiles
FOR UPDATE
USING (auth.uid() = id);

When a client queries via the REST API, Supabase:

  1. Validates the JWT from the request
  2. Sets the auth.uid() session variable
  3. Applies RLS policies before returning data

Auto-Generated REST API

PostgREST introspects the PostgreSQL schema and generates a RESTful API:

# Automatic endpoints from schema
GET    /todos                    # List all todos
GET    /todos?id=eq.1            # Filter by id
POST   /todos                    # Create todo
PATCH  /todos?id=eq.1            # Update todo
DELETE /todos?id=eq.1            # Delete todo

# Resource embedding (joins)
GET    /todos?select=*,users(*)

Supavisor Connection Pooling

Serverless functions create connection storms. Supavisor solves this:

Mode Description Use Case
Transaction Mode Lease connection per query Serverless, HTTP APIs
Session Mode Dedicated connection per client Prepared statements, temp tables

Deprecation Note: Session Mode on port 6543 deprecated February 28, 2025.

Realtime Data Synchronization

Three modes of real-time communication:

Mode Throughput Latency Use Case
Broadcast 224K msg/sec 6ms median Cursors, ephemeral events
Presence High Low User status, typing indicators
Postgres Changes ~64 changes/sec Higher Chat, notifications

Vector Search (pgvector)

Supabase integrates pgvector for AI applications:

Index Options:

  • HNSW: High recall, fast queries, more memory
  • IVFFlat: Faster builds, lower recall

Hybrid Search: Combine keyword (BM25) + semantic (vector):

SELECT title, content,
  ts_rank(textsearch, query) AS rank_text,
  embedding <=> '[0.1, 0.5, ...]' AS distance_vector
FROM documents,
  to_tsquery('english', 'search query') query
WHERE textsearch @@ query
ORDER BY rank_text + distance_vector DESC
LIMIT 10;

Supabase vs Competitors

Supabase vs Firebase

Feature Supabase Firebase
Database PostgreSQL (relational) Firestore (NoSQL)
SQL Support Full SQL No (NoSQL query syntax)
Portability Standard Postgres dump Proprietary
Realtime Via WAL replication Native listeners
Pricing Generous free tier Usage-based scales quickly

Supabase vs Neon

Feature Supabase Neon
Focus Complete BaaS platform Database-only
Branching Manual database clones Instant metadata branching
Scale-to-Zero No (7-day pause on free) Yes (5-min timeout)
Auth/Realtime Built-in Via integrations

Supabase vs Appwrite

Feature Supabase Appwrite
Database PostgreSQL MongoDB/MySQL/PostgreSQL
Runtime Deno (Edge) Docker containers
Storage S3-compatible Built-in object storage
Mobile SDKs Official (iOS, Android, Flutter) Official

Edge Functions (Deno)

Supabase Edge Functions use the Deno runtime:

// Supabase Function
import { serve } from "https://deno.land/std@0.168.0/http/server.ts";

serve(async (req) => {
  const data = await req.json();
  return new Response(JSON.stringify(data), {
    headers: { "Content-Type": "application/json" }
  });
});

Limits:

  • Memory: 256MB
  • CPU Time: 2 seconds soft limit
  • Wall-clock: 400 seconds (paid plans)

Note: Deploying Supabase Edge Functions via Vercel is officially unsupported. Deploy directly to Supabase platform.

Client SDKs

Platform Status Notes
Web (JS/TS) Official SSR support via @supabase/ssr
iOS (Swift) Official Native concurrency, SwiftUI optimized
Flutter (Dart) Official First-class support, deep linking
Android (Kotlin) Community supabase-kt (KMP support)
Python Official (Beta) Growing for data science

Server-Side Rendering

The @supabase/ssr package manages authentication cookies:

import { createServerClient } from '@supabase/ssr'

export async function createClient() {
  return createServerClient(
    process.env.NEXT_PUBLIC_SUPABASE_URL!,
    process.env.NEXT_PUBLIC_SUPABASE_ANON_KEY!,
    {
      cookies: {
        getAll() { return cookies().getAll() },
        setAll(cookiesToSet) {
          cookiesToSet.forEach(({ name, value, options }) =>
            cookies().set(name, value, options)
          )
        }
      }
    }
  )
}

ORM Support

ORM Integration Notes
Drizzle First-class Preferred for Supabase ecosystem
Prisma Supported Configure for Supavisor pooler
Sequelize Supported Considered legacy

Pricing Structure

Tier Monthly Cost Database MAU Storage Log Retention
Free $0 500 MB 50K 1 GB 1 day
Pro $25 8 GB 100K 100 GB 7 days
Team $599 Dedicated 100K+ 100 GB+ 28 days

Free Tier Caveat: Projects pause after 1 week of inactivity.

Hidden Costs:

  • Compute upgrade: Micro to Large = +$110/month
  • IPv4 address: $4/month
  • High IOPS disks: io2 storage adds cost

Operational Limits

Limit Value
Disk IO Baseline ~87 Mbps (Micro), 500 IOPS
Burst Duration ~30 minutes before throttle
Auth Rate Limit 360 requests/hour per IP (verify endpoint)
Max rows returned 1000 (default), configurable

Use Cases: Best For

  • SaaS Applications: Multi-tenant with RLS isolation
  • Next.js Apps: First-class SSR support
  • AI Applications: pgvector + relational data in one DB
  • Rapid Prototyping: Auto-generated API accelerates development
  • Open Source Preference: Data exportable as standard Postgres dump

Use Cases: Avoid For

  • Massive Analytics: Use ClickHouse or dedicated OLAP
  • High-Frequency Firehose: Postgres Changes limited to ~64 changes/sec
  • Teams Needing Firebase Sync: Different real-time model

FAQ

Is Supabase free?

Supabase offers a free tier with 500MB database, 50K MAU, and 1GB storage. Projects pause after 7 days of inactivity. The Pro tier starts at $25/month.

Can I use Supabase with Vercel?

Yes, Supabase integrates well with Vercel. Use @supabase/ssr for server-side rendering in Next.js. However, Supabase Edge Functions must be deployed to Supabase, not Vercel.

Does Supabase support PostgreSQL?

Supabase is built entirely on PostgreSQL. You get a full, isolated PostgreSQL instance with access to all features: extensions, functions, triggers, and standard SQL.

What is the difference between Supabase and Neon?

Supabase is a full BaaS platform (database + auth + realtime + storage). Neon is a database-only service with serverless features like branching and scale-to-zero. Supabase uses Neon-like architecture for some offerings.

Yes, Supabase includes pgvector support. Create HNSW or IVFFlat indexes for vector similarity search. Supabase also provides an Index Advisor AI tool for optimization.

Related Technologies: PostgreSQL, Neon, Firebase, Appwrite, Prisma, Drizzle ORM, Next.js

Updated:

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