Bun is an all‑in‑one toolkit for JavaScript and TypeScript that combines a high‑performance runtime, a fast npm‑compatible package manager, a native bundler, and a Jest‑compatible test runner. It offers built‑in APIs for HTTP, WebSocket, SQL, Redis, S3, and more, allowing developers to replace multiple external tools with a single, Node.js‑compatible stack that speeds up development, builds, and testing.
Funding
$7M raised to dateRaised to date based on public sources. This may differ from the amount the company actually raised and is based only on what is publicly available on the internet.
1OFounders
Product
Problem
JavaScript developers often have to stitch together multiple separate tools—runtime, package manager, bundler, and test runner—to build, run, and deploy applications, leading to slower development cycles, inconsistent performance, and compatibility issues with Node.js ecosystems.
Solution
Bun delivers an all‑in‑one, incrementally adoptable toolkit that combines a high‑performance JavaScript/TypeScript runtime, a fast npm‑compatible package manager, a native bundler, and a Jest‑compatible test runner. Each component can be used independently (e.g., bun install in an existing Node project) or together as a unified stack, providing seamless 100 % Node.js compatibility while offering dramatically lower startup, build, and test times. Built‑in APIs such as HTTP server, WebSocket server, SQL drivers, Redis client, S3 storage, and image processing eliminate the need for external libraries, reducing dependency bloat and simplifying deployment. The toolkit also supports plugins, hot‑reloading, monorepo workspaces, and single‑file executable generation, enabling developers to iterate faster and ship smaller, more reliable binaries.
Target Audience
Primary users are JavaScript/TypeScript developers building web applications, APIs, serverless functions, or full‑stack projects who want a faster, more integrated development workflow and high Node.js compatibility.
Features
- Lightning‑fast runtime built on WebKit’s JavaScriptCore, offering faster startup than V8‑based Node.js
- Bun install: a drop‑in npm‑compatible package manager with global virtual store, workspaces, and optimized file writes
- Native bundler (bun build) with support for TypeScript, JSX, CSS, HTML, and custom loaders via a plugin API
- Built‑in test runner (bun test) with Jest‑compatible API, concurrent execution, watch mode, and CI/CD integrations
- Comprehensive standard library: HTTP/HTTPS server, WebSocket server, routing, HTML imports, and hot‑reloading
- Unified database APIs: PostgreSQL, MySQL, SQLite drivers with tagged‑template literals, connection pooling, and transactions
- Native Redis client with Promise‑based API, Pub/Sub, and automatic pipelining
- Built‑in S3 client, image processing (Bun.Image) supporting multiple formats without native modules
- Single‑file executable generation for easy distribution of CLI tools and serverless functions