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If you’ve been working with Node for a while, you probably have a pretty solid workflow. You know the quirks. You’ve got your go-to tools. And everything kind of works… after a bit of setup, a bunch of config files, and maybe some yelling at Webpack.
But recently, a lot of devs have been messing around with this new runtime called Bun, and the feedback is loud: it’s fast, it’s simple, and it just makes writing JavaScript feel smoother.
So what’s the deal? Why are people trying out Bun when Node already gets the job done?
Here’s what’s really going on.
First off, what even is Bun?
At its core, Bun is a JavaScript runtime. Just like Node. But it’s trying to do a lot more, all in one go. It’s built from scratch using a language called Zig, and it doesn’t use Chrome’s V8 engine like Node does. Instead, it runs on Apple’s JavaScriptCore, which is what powers Safari.
That might not sound like a huge deal at first, but it actually changes a lot.
What makes Bun different is how it tries to cut out all the stuff you normally have to piece together in Node. It’s not just a runtime. It also gives you:
A fast package manager (bun install)A built-in test runner
A bundler
TypeScript and JSX support
And a simple HTTP server
With Node, you’d usually need npm or Yarn, plus maybe ts-node, Babel, Jest, Webpack, and a couple other tools depending on your stack. Bun bakes it all into one thing. So you’re not duct-taping six tools together just to write some code.
Is it really that fast?
Yeah, it actually is. This isn’t one of those things where you have to squint at benchmarks to notice a difference. It’s fast in a way you can feel the second you start using it.
Here’s a real-world example. Try installing React and React DOM:
That’s not marketing spin. It’s just better at caching and doing less unnecessary work.
And it’s not just installs. Starting a dev server, running tests, bundling — everything just kicks off instantly. It feels like using Vite for the first time after struggling with Webpack. Same kind of “why wasn’t it always this fast?” moment.
The developer experience is clean
Let’s say you want to spin up a simple server with Node and TypeScript. You’ll probably need a tsconfig.json, an HTTP library like Express or Fastify, and something to run the TypeScript.
Now here’s the same thing with Bun:
const server = Bun.serve({
port: 3000,
fetch(req) {
return new Response("Hello from Bun");
}
}); No imports. No third-party server. No transpiler setup. You just write TypeScript and run it.
It feels weird at first because you’re expecting it to ask for more setup, but it just works. And that’s kind of the theme with Bun — you write less boilerplate, and it just runs.
Built-in testing is actually nice
You don’t need Jest anymore. Bun ships with a basic but solid test runner. And yeah, it works with async functions, has support for beforeEach, and you can do simple mocking.
test("adds numbers", () => {
expect(1 + 2).toBe(3);
});
That’s the whole thing. You run bun test and you’re good.
If you’ve ever lost 30 minutes trying to get Jest to work with ES modules or TypeScript paths, you’ll appreciate how smooth this feels.
But it’s not perfect
Bun’s still new, and there are things you’ll run into that aren’t 100% polished yet.
- Some Node packages won’t work, especially ones that depend on native modules or deep V8 internals.
- Debugging support isn’t as good as Node’s right now. No Chrome DevTools integration yet.
- There are a few rough edges with ESM/CommonJS compatibility. Most of the big stuff works, but edge cases pop up.
If you’re building something massive in Node, with lots of legacy dependencies and stuff that’s already battle-tested, you might not want to switch just yet.
But if you’re starting something new? Especially a personal project, a CLI, or even a backend service? Bun’s a legit option.
Who’s using it?
Bun’s been moving fast. The team pushes updates constantly, and the ecosystem is picking up.
A few frameworks and tools are already supporting it or testing it out:
- SolidJS works with it
- Astro is looking into it
- A bunch of Vite alternatives are experimenting with Bun under the hood
- Some folks are even writing full-stack apps using just Bun and HTMX or Preact
Most of the people using it right now are early adopters — indie hackers, OSS maintainers, or startup devs looking to cut dev time.
But it’s growing. And it’s stable enough for serious use, especially in places where you control the stack.
Should you switch?
Here’s the simple take:
- If you’re maintaining a huge production Node app, maybe just try Bun in a side project first.
- If you’re building something new, definitely try it out. You’ll probably like it.
- If you’re tired of waiting for npm to install stuff or messing with config files just to get TypeScript and JSX running, Bun is gonna feel like a breath of fresh air.
It doesn’t replace Node everywhere. Yet. But it definitely replaces it somewhere. And that “somewhere” is growing.