Bun in 2026: The All-in-One JavaScript Runtime

Bun bundles a runtime, package manager, bundler, and test runner into a single fast binary built on JavaScriptCore. In 2026 it's a serious Node alternative for the right workloads. Here's the honest picture.

What Makes It Fast

• Built on JavaScriptCore (not V8) with a native core written in Zig.
• bun install is dramatically faster than npm for cold installs.
• First-class TypeScript and JSX — run .ts files with no build step.

A Built-In HTTP Server

Bun.serve({
  port: 3000,
  fetch(req) {
    return new Response("Hello from Bun");
  },
});

Drop-In Tooling

bun install        # package manager
bun run dev        # script runner
bun test           # test runner
bun build ./app.ts # bundler