Can Bun.js Beat Node.js and Deno?

Bun is fast — everyone knows that.
But speed alone doesn’t win ecosystems.
Let’s look at what Bun actually does better, where it falls short, and whether it can dethrone Node/Deno.

1. Why Bun Is Fast

Bun uses Zig, a low-level systems language.
It ships with:

• Built-in bundler
• Built-in transpiler
• Built-in test runner
• Built-in runtime

No npm + webpack + Jest + Babel chain.
Everything is native.

Example Benchmark

node server.js   # ~35k req/s
bun server.js    # ~180k req/s
deno server.ts   # ~70k req/s

The numbers speak for themselves.

2. Node.js Strengths

Node wins in:

• Ecosystem size
• Stability
• Enterprise adoption
• Package compatibility
• Long-term support

99% of all JS backend packages were written assuming Node behavior.

3. Deno Strengths

Deno shines with:

• Native TypeScript
• Secure-by-default runtime
• Better standard library
• Built-in tooling

But adoption has been slow.

4. Bun Problems (Right Now)

1. Slight ecosystem instability

Breaking changes still happen.

2. Not all npm packages work

Even though compatibility is improving.

3. Hosting support is limited

Node still dominates serverless platforms.

5. Will Bun actually win?

Yes — for developers building:

• High‑performance APIs
• Real‑time apps
• Local dev tools
• CLIs

No — for:

• Enterprise-grade apps
• Large teams that value stability
• Legacy Node projects

6. Simple Bun HTTP Server Example

export default {
  port: 3000,
  fetch(req) {
    return new Response("Hello from Bun!");
  },
};

Final Verdict

Bun won’t kill Node or Deno.
But it will push the entire JavaScript runtime ecosystem forward — and that’s a win for everyone.