Bun — A fast all-in-one JavaScript runtime
Bun is a Javascript runtime, compiler, transpiler, bundler, test runner, and standard library. That’s quite an all-in-one tool.
If you want a TLDR, bun calls itself a “drop-in replacement for Node.js”.
It’s an all-in-one framework that replaces:
- Node.js
- npm
- tsc
- Jest/Vitest
- Babel/Webpack
So you can get rid of dependencies, build tools, and .config files and have everything in one place.
Bun is fast. Very fast. Compared to Node.js (Benchmarks oh sigh!, take it with a good grain of salt)
- Serves 4x more HTTP requests per second
- Sends 5x more WebSocket msgs per second
- Handles 4x more SQL queries per second
Bun is written in Zig and uses Apple’s JS Core instead of Chrome’s V8. And that’s one of the major reasons for its outstanding speed.
Why it could be a game changer and a much needed one in the JS/TS community
1. Typescript and JSX out-of-the-boxThis is the biggest one for me.
Just create an index.ts file, write some code, and and call bun run. That’s it.
2. No more module madness
Every seasoned Node developer has had a painful experience with ESM vs. Common JS.
No need to…
- Compile to an output dir and run the js file
- Set up ts-node to run files on the fly
- Configure complicated tsconfig settings
- Worry about ts-jest and how Typescript affects your test suite
With Bun you can import, require, use top-level awaits, and intermix as you want.
No need to deal with modules or resolution priorities.
3. Built-in Utiltiies
Bun has a ton of built-in utilities
- Watch mode
- A Javascript repl
- Zero-Config SQLite database
- Websocket servers
There are currently over 1.9k issues open on Github!
If you’re trying to build an incredibly stable, reliable, fail-proof system, then you might want to give it a few more months to settle in.
We’re only at v1 after all.
But if you’re looking for a way to quickly, efficiently, and delightfully run your Javascript apps, then Bun is something you should bag in your toolkit.
So excited to see what’s ahead.
-Rushi