# PGlite — Embeddable Postgres in WebAssembly

> PGlite is an embeddable PostgreSQL build that runs in the browser, Node.js, and Bun via WebAssembly, giving you a full Postgres engine under 3MB with real-time reactive queries.

## Install

Save in your project root:

# PGlite — Embeddable Postgres in WebAssembly

## Quick Use
```bash
npm install @electric-sql/pglite
```
```javascript
import { PGlite } from "@electric-sql/pglite";
const db = new PGlite();
await db.query("SELECT 'Hello, PGlite' AS greeting;");
```

## Introduction
PGlite packages a real PostgreSQL engine into a WebAssembly build that runs directly in the browser or server-side JavaScript runtimes. It provides full SQL compatibility with Postgres in a lightweight embeddable package, ideal for local-first apps, testing, and prototyping.

## What PGlite Does
- Runs a complete PostgreSQL instance in the browser with no server required
- Works in Node.js, Bun, and Deno for server-side embedded use cases
- Supports persistent storage via IndexedDB in the browser or filesystem on the server
- Provides reactive live queries that re-execute when underlying data changes
- Includes extension support for pgvector, PostGIS, and full-text search

## Architecture Overview
PGlite compiles the PostgreSQL C source code to WebAssembly using Emscripten. The resulting WASM module runs in any JavaScript environment with a virtual filesystem layer that maps to IndexedDB (browser) or the real filesystem (Node.js). A TypeScript wrapper provides the query API, connection pooling, and the reactive live-query layer built on top of logical replication.

## Self-Hosting & Configuration
- Install via npm as a standard JavaScript dependency
- No external PostgreSQL server or Docker container needed
- Configure storage backend (in-memory, IndexedDB, or filesystem) at initialization
- Load extensions like pgvector by importing the corresponding PGlite extension package
- Works in serverless environments including Cloudflare Workers and Vercel Edge Functions

## Key Features
- Full PostgreSQL wire protocol compatibility in under 3MB compressed
- Reactive live queries that push updates when data changes
- Extension ecosystem including pgvector for AI embeddings
- Zero-dependency local-first storage for offline-capable applications
- TypeScript-first API with full type inference

## Comparison with Similar Tools
- **sql.js (SQLite WASM)** — SQLite compiled to WASM; simpler but lacks Postgres features like JSONB, window functions, and extensions
- **libSQL / Turso** — SQLite fork with server sync; different SQL dialect and extension model
- **DuckDB WASM** — Analytical query engine in WASM; optimized for OLAP, not transactional workloads
- **CockroachDB** — Distributed Postgres-compatible database; requires server infrastructure
- **SurrealDB** — Multi-model database with embedded mode; uses its own query language, not standard SQL

## FAQ
**Q: Is PGlite a full PostgreSQL implementation?**
A: Yes, PGlite compiles the actual PostgreSQL source code to WebAssembly. It supports the vast majority of PostgreSQL features and SQL syntax.

**Q: Can I use PGlite for production applications?**
A: PGlite is well-suited for local-first apps and embedded use cases. For multi-user server workloads, a traditional PostgreSQL deployment is recommended.

**Q: How large is the PGlite WASM bundle?**
A: The compressed bundle is under 3MB, making it practical for browser-based applications.

**Q: Does PGlite support migrations?**
A: PGlite runs standard PostgreSQL DDL, so any migration tool that generates SQL (Drizzle, Prisma, raw SQL) works with it.

## Sources
- https://github.com/electric-sql/pglite
- https://pglite.dev

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Source: https://tokrepo.com/en/workflows/79e9cd68-3c71-11f1-9bc6-00163e2b0d79
Author: AI Open Source