Bun vs Node.js in 2026: Is It Worth Migrating? Real Benchmarks and Experiences

Hello HaWkers, in 2026 the question many developers are asking is: should I migrate my projects from Node.js to Bun? With Bun 1.2 achieving near-complete compatibility with Node.js APIs and significantly superior performance, this question has become much more relevant.

Let's analyze real data, benchmarks, and experiences from teams that have already made this migration.

The Current State of Bun in 2026

Bun has evolved from an experimental project to a legitimate Node.js alternative. Version 1.2, released in early 2026, brought compatibility with over 95% of Node.js APIs.

Important milestones:

Complete support for complex native modules (buffer, fs, path)
Express, Fastify, and most middlewares work without changes
Integrated package manager faster than npm, yarn, and pnpm
Native bundler and test runner

💡 Fact: Bun was built from scratch in Zig with JavaScriptCore (Safari engine), while Node.js uses V8 (Chrome engine).

Real 2026 Benchmarks

The performance numbers are impressive:

HTTP Server Performance

In Express-style tests, Bun sustains approximately 52,000 requests per second while Node.js plateaus at 13,000.

Metric	Bun 1.2	Node.js 24
Requests/s	~52,000	~13,000
Avg response time	157ms	620ms
Failure rate	0%	0.2%

CPU-Bound Operations

CPU-intensive work shows similar difference: generating and sorting 100,000 numbers takes 1,700ms on Bun versus 3,400ms on Node.

Startup Time

Bun starts significantly faster - crucial for serverless and CLI tools:

Scenario	Bun	Node.js
Simple cold start	~15ms	~150ms
Basic Express app	~50ms	~400ms
Lambda cold start	~80ms	~600ms

Real Migration Experiences

Teams that migrated from Node.js to Bun report varied but generally positive results:

Case 1: Serverless Cost Reduction

One team reduced their Lambda function execution duration by 35% when migrating to Bun, directly impacting AWS costs.

Case 2: Complete Repo Migration

Some teams completed full migrations from Node to Bun across all repositories:

What worked without issues:

Express and Fastify
Prisma and other ORMs
Jest (with bun test as alternative)
Most middlewares

What needed workarounds:

Some native addons like bcrypt and sharp
Packages that depend on V8-specific behaviors

How to Decide: Bun or Node.js?

When to Choose Bun

Greenfield projects:

If you're starting a new project, Bun offers zero-config and superior speed
Simpler setup justifies the smaller compatibility risk

CLI tools and scripts:

Drastically lower startup time makes a real difference
Integrated package manager simplifies tooling

Serverless functions:

Faster cold starts = lower latency and lower cost
Especially advantageous for frequently executed functions

// Example: Simple API in Bun
const server = Bun.serve({
  port: 3000,
  fetch(req) {
    const url = new URL(req.url);

    if (url.pathname === '/api/health') {
      return Response.json({ status: 'ok', runtime: 'bun' });
    }

    if (url.pathname === '/api/users') {
      // Bun has native optimized fetch
      return Response.json([
        { id: 1, name: 'Alice' },
        { id: 2, name: 'Bob' }
      ]);
    }

    return new Response('Not Found', { status: 404 });
  }
});

console.log(`Server running at http://localhost:${server.port}`);

When to Keep Node.js

Established enterprise projects:

Node.js ecosystem depth is still superior
Easier to find developers with experience

When security is critical:

Node.js has permission model (--allow-fs-read, etc.)
Bun runs with full system access by default
For security sandboxing, Deno remains the best option

Dependencies with complex native addons:

Some packages still don't work 100% on Bun
Check compatibility before migrating

Recommended Migration Strategy

If you decide to migrate, here's a safe approach:

1. Migrate Incrementally

Don't migrate everything at once:

# Start with CLI tools
cd my-cli-tool && bun install && bun run

# Then move to backend services
cd my-api && bun install && bun run dev

# Finally, production
bun run build && bun run start

2. Isolate Platform-Specific Code

// utils/runtime.js
export const isBun = typeof Bun !== 'undefined';
export const isNode = typeof process !== 'undefined' && !isBun;

export async function readFile(path) {
  if (isBun) {
    return Bun.file(path).text();
  }
  const fs = await import('fs/promises');
  return fs.readFile(path, 'utf-8');
}

3. Migrate Tests First

Validate behavior through tests before switching runtime in production:

// package.json - dual support
{
  "scripts": {
    "test": "jest",
    "test:bun": "bun test"
  }
}

What About Deno?

It's worth mentioning that Deno 2 is also an option in 2026, with its own set of trade-offs:

Aspect	Bun	Node.js	Deno 2
Performance	Excellent	Good	Very Good
npm compatibility	95%+	100%	90%+
Security (sandbox)	No	Partial	Yes
Native TypeScript	Yes	No	Yes
Ecosystem	Growing	Mature	Medium

Conclusion

The choice between Bun and Node.js in 2026 comes down to: flexibility (Node.js) versus velocity (Bun).

Greenfield projects benefit from Bun's zero-config approach, while enterprise builds with unique requirements need Node.js's ecosystem depth.

For new projects, trying Bun makes sense - the speed justifies the smaller compatibility risks. For existing projects, carefully evaluate your dependencies before migrating.

If you're interested in JavaScript performance, I recommend checking out another article: TypeScript 7 Native in Go: 10x Faster where you'll discover how TypeScript itself is being rewritten for better performance.