<div id="readability-page-1" class="page"><div><img src="https://devstarsj.github.io/assets/https://images.unsplash.com/photo-1627398242454-45a1465c2479?w=1200&amp;q=80"><h2 id="three-runtimes-one-language">Three Runtimes, One Language</h2>JavaScript on the server has never had more options — or more confusion. In 2026, developers choosing a backend JS runtime face a genuinely competitive three-way race:<ul><li>Node.js 24 — the incumbent with 15 years of ecosystem baggage and battle-tested production pedigree</li><li>Deno 2 — Ryan Dahl’s redemption arc, now with Node.js compatibility and the JSR package registry</li><li>Bun 1.x — the speed-obsessed newcomer built on JavaScriptCore, aiming to replace the entire JS toolchain</li></ul>This isn’t a “which is best” post — each runtime has a legitimate place in the ecosystem. This is a guide to making the right choice for your use case.<img src="https://images.unsplash.com/photo-1555099962-4199c345e5dd?w=900&amp;q=75" alt="JavaScript code on screen"> Photo by <a href="https://unsplash.com/@markusspiske">Markus Spiske</a> on Unsplash<hr><h2 id="the-quick-comparison">The Quick Comparison</h2><table><thead><tr><th>Feature</th><th>Node.js 24</th><th>Deno 2</th><th>Bun 1.x</th></tr></thead><tbody><tr><td>Engine</td><td>V8</td><td>V8</td><td>JavaScriptCore</td></tr><tr><td>TypeScript</td><td>Via transpile</td><td>Native</td><td>Native</td></tr><tr><td>npm compat</td><td>✅ Native</td><td>✅ (<code>npm:</code> specifier)</td><td>✅ Native</td></tr><tr><td>Security sandbox</td><td>❌</td><td>✅ (permissions)</td><td>❌</td></tr><tr><td>Built-in test runner</td><td>✅ (<code>node:test</code>)</td><td>✅</td><td>✅</td></tr><tr><td>Package manager</td><td>npm/yarn/pnpm</td><td><code>deno</code> / <code>npm:</code></td><td><code>bun</code> (built-in)</td></tr><tr><td>HTTP server</td><td><code>node:http</code></td><td><code>Deno.serve()</code></td><td><code>Bun.serve()</code></td></tr><tr><td>Cold start</td><td>~40ms</td><td>~20ms</td><td>~8ms</td></tr><tr><td>Startup memory</td><td>~35MB</td><td>~25MB</td><td>~15MB</td></tr><tr><td>Edge deployment</td><td>Partial</td><td>Deno Deploy</td><td>Bun on Fly/Render</td></tr></tbody></table><hr><h2 id="nodejs-24-the-mature-giant">Node.js 24: The Mature Giant</h2>Node.js 24 (released April 2026) ships with:<ul><li>V8 12.8 — the latest engine with Maglev JIT on by default</li><li><code>node:sqlite</code> — built-in SQLite module (no more <code>better-sqlite3</code>)</li><li>Type stripping — run <code>.ts</code> files directly with <code>--experimental-strip-types</code></li><li><code>Permission Model</code> — a Deno-inspired, opt-in sandbox (still experimental)</li></ul><div><pre><code>// node:sqlite — finally built-in!
import { DatabaseSync } from 'node:sqlite';

const db = new DatabaseSync(':memory:');
db.exec('CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT)');

const insert = db.prepare('INSERT INTO users (name) VALUES (?)');
insert.run('Alice');
insert.run('Bob');

const all = db.prepare('SELECT * FROM users').all();
console.log(all); // [{ id: 1, name: 'Alice' }, { id: 2, name: 'Bob' }]
</code></pre></div>When to choose Node.js:<ul><li>You have an existing large codebase</li><li>Your dependencies use native addons (<code>.node</code> files)</li><li>Your team is deeply familiar with the npm ecosystem</li><li>You need maximum production maturity and enterprise support</li></ul><hr><h2 id="deno-2-the-permission-first-runtime">Deno 2: The Permission-First Runtime</h2>Deno 2 (released late 2024) was the pivot that made Deno serious:<ul><li>Full npm compatibility via <code>npm:</code> specifiers</li><li>Node.js API compatibility via <code>node:</code> module emulation</li><li>JSR (JavaScript Registry) — a TypeScript-first, security-reviewed package registry</li><li><code>deno compile</code> — bundle your app to a single self-contained executable</li></ul><div><pre><code>// Deno 2: security by default
// This script needs --allow-net and --allow-read to run

const response = await fetch("https://api.example.com/data");
const data = await response.json();

// Write to filesystem — requires explicit --allow-write
await Deno.writeTextFile("output.json", JSON.stringify(data, null, 2));
console.log("Done!");
</code></pre></div>Run with scoped permissions:<div><pre><code>deno run \
 --allow-net=api.example.com \
 --allow-write=./output.json \
 main.ts
</code></pre></div><h3 id="jsr-a-better-npm">JSR: A Better npm?</h3>JSR deserves special attention. Unlike npm, every package on JSR:<ul><li>Must be TypeScript (or provide full type declarations)</li><li>Is scored for documentation quality</li><li>Is scoped by default (<code>@scope/package</code>)</li><li>Supports multiple runtimes (Deno, Node, Bun, Cloudflare Workers)</li></ul><div><pre><code># Add a JSR package to a Node.js project
npx jsr add @std/datetime

# Add to Deno project
deno add @std/datetime
</code></pre></div>When to choose Deno:<ul><li>Security is a top concern (financial services, healthcare)</li><li>You want modern TypeScript-first development</li><li>You’re deploying to Deno Deploy (edge runtime with zero config)</li><li>You want the <code>deno compile</code> single-binary distribution story</li></ul><hr><h2 id="bun-speed-as-a-philosophy">Bun: Speed as a Philosophy</h2>Bun’s thesis is that JavaScript tooling is too slow and too fragmented. Instead of a runtime, Bun is a complete JavaScript toolkit in a single binary:<ul><li>Runtime (JavaScriptCore-based)</li><li>Package manager (faster than pnpm in most benchmarks)</li><li>Bundler (faster than esbuild for most configs)</li><li>Test runner</li><li>TypeScript transpiler</li></ul><h3 id="http-server-performance">HTTP Server Performance</h3>Bun’s <code>Bun.serve()</code> consistently leads benchmarks:<div><pre><code>// Bun HTTP server
const server = Bun.serve({
 port: 3000,
 fetch(req) {
 const url = new URL(req.url);
 
 if (url.pathname === "/health") {
 return new Response("OK");
 }
 
 if (url.pathname === "/json") {
 return Response.json({ 
 message: "Hello from Bun!",
 timestamp: Date.now()
 });
 }
 
 return new Response("Not Found", { status: 404 });
 },
});

console.log(`Listening on http://localhost:${server.port}`);
</code></pre></div>Benchmark results (requests/sec, simple JSON endpoint, Apple M3 Pro):<table><thead><tr><th>Runtime</th><th>req/s</th></tr></thead><tbody><tr><td>Bun 1.x</td><td>~285,000</td></tr><tr><td>Node.js 24 (uWebSockets)</td><td>~220,000</td></tr><tr><td>Deno 2</td><td>~195,000</td></tr><tr><td>Node.js 24 (http module)</td><td>~85,000</td></tr></tbody></table><h3 id="buns-sqlite">Bun’s SQLite</h3><div><pre><code>import { Database } from "bun:sqlite";

const db = new Database("mydb.sqlite");
const query = db.query("SELECT * FROM users WHERE age &gt; $age");
const users = query.all({ $age: 18 });
</code></pre></div>When to choose Bun:<ul><li>Startup time matters (CLI tools, lambdas, edge functions)</li><li>You want to drop npm/yarn/pnpm/esbuild/jest in one move</li><li>You’re starting fresh with no legacy constraints</li><li>Your team values speed of development over ecosystem maturity</li></ul><hr><h2 id="real-world-decision-framework">Real-World Decision Framework</h2><h3 id="building-an-apimicroservice">Building an API/microservice?</h3><ul><li>Need maximum ecosystem compat → Node.js + Fastify or Hono</li><li>Need security isolation → Deno + Oak/Hono</li><li>Need maximum throughput → Bun + Elysia</li></ul><h3 id="building-a-cli-tool">Building a CLI tool?</h3><ul><li>Distributing as binary → Deno (<code>deno compile</code>) or Bun (<code>bun build --compile</code>)</li><li>Publishing to npm → Node.js (widest install base)</li></ul><h3 id="serverlessedge-functions">Serverless/Edge functions?</h3><ul><li>Cloudflare Workers → All three work, Deno’s API closest to WinterCG spec</li><li>Deno Deploy → Deno obviously</li><li>AWS Lambda → Node.js (official runtime), Bun (custom runtime layer)</li></ul><h3 id="monorepo--full-stack">Monorepo + full-stack?</h3><ul><li>Next.js/Remix → Node.js or Bun (better compatibility)</li><li>Fresh (Deno) → Deno</li></ul><hr><h2 id="interoperability-in-2026">Interoperability in 2026</h2>The good news: all three runtimes are converging on the <a href="https://wintercg.org/">WinterCG (Web-interoperable Runtimes Community Group)</a> standard. This means:<ul><li><code>fetch</code>, <code>Request</code>, <code>Response</code> — identical across all three</li><li><code>URL</code>, <code>URLSearchParams</code> — standardized</li><li><code>crypto.subtle</code> — identical Web Crypto API</li><li><code>ReadableStream</code>, <code>WritableStream</code> — standard Streams API</li></ul>Libraries that target WinterCG work on all three runtimes. Hono, for example, is a popular framework that runs identically on Node.js, Deno, Bun, and Cloudflare Workers.<hr><h2 id="conclusion">Conclusion</h2>Stop asking which runtime is “best” and start asking which runtime is best for your context:<ul><li>Node.js 24 is the safe, mature choice with the most ecosystem support</li><li>Deno 2 is the right choice when security, TypeScript DX, and modern tooling matter</li><li>Bun is the right choice when speed — of runtime and of developer tooling — is the priority</li></ul>In 2026, you can also mix runtimes per service in a microservices architecture. WinterCG compatibility means sharing business logic across them is increasingly tractable.<hr>References:<ul><li><a href="https://nodejs.org/en/blog/release/">Node.js Changelog</a></li><li><a href="https://deno.com/blog/v2.0">Deno 2 Release Notes</a></li><li><a href="https://bun.sh/docs">Bun Documentation</a></li><li><a href="https://jsr.io/">JSR Registry</a></li><li><a href="https://wintercg.org/">WinterCG</a></li></ul> <div>이 글이 도움이 되셨다면 공감 및 광고 클릭을 부탁드립니다 :) </div></div></div>

Dev Note

Three Runtimes, One Language
JavaScript on the server has never had more options — or more confusion. In 2026, developers choosing a backend JS runtime face a genuinely competitive three-way race:
Node.js 24 — the incumbent with 15 years of ecosystem baggage and battle-tested production pedigree
Deno 2 — Ryan Dahl’s redemption arc, now with Node.js compatibility and the JSR package registry
Bun 1.x — the speed-obsessed newcomer built on JavaScriptCore, aiming to replace the entire JS toolchain
This isn’t a “which is best” post — each runtime has a legitimate place in the ecosystem. This is a guide to making the right choice for your use case.
Photo by Markus Spiske on Unsplash
The Quick Comparison
Feature
      Node.js 24
      Deno 2
      Bun 1.x
    
Engine
      V8
      V8
      JavaScriptCore
    
TypeScript
      Via transpile
      Native
      Native
    
npm compat
      ✅ Native
      ✅ (npm: specifier)
      ✅ Native
    
Security sandbox
      ❌
      ✅ (permissions)
      ❌
    
Built-in test runner
      ✅ (node:test)
      ✅
      ✅
    
Package manager
      npm/yarn/pnpm
      deno / npm:
      bun (built-in)
    
HTTP server
      node:http
      Deno.serve()
      Bun.serve()
    
Cold start
      ~40ms
      ~20ms
      ~8ms
    
Startup memory
      ~35MB
      ~25MB
      ~15MB
    
Edge deployment
      Partial
      Deno Deploy
      Bun on Fly/Render
    
Node.js 24: The Mature Giant
Node.js 24 (released April 2026) ships with:
V8 12.8 — the latest engine with Maglev JIT on by default
node:sqlite — built-in SQLite module (no more better-sqlite3)
Type stripping — run .ts files directly with --experimental-strip-types
Permission Model — a Deno-inspired, opt-in sandbox (still experimental)
// node:sqlite — finally built-in!
import { DatabaseSync } from 'node:sqlite';
const db = new DatabaseSync(':memory:');
db.exec('CREATE TABLE users (id INTEGER PRIMARY KEY, name TEXT)');
const insert = db.prepare('INSERT INTO users (name) VALUES (?)');
insert.run('Alice');
insert.run('Bob');
const all = db.prepare('SELECT * FROM users').all();
console.log(all); // [{ id: 1, name: 'Alice' }, { id: 2, name: 'Bob' }]
When to choose Node.js:
You have an existing large codebase
Your dependencies use native addons (.node files)
Your team is deeply familiar with the npm ecosystem
You need maximum production maturity and enterprise support
Deno 2: The Permission-First Runtime
Deno 2 (released late 2024) was the pivot that made Deno serious:
Full npm compatibility via npm: specifiers
Node.js API compatibility via node: module emulation
JSR (JavaScript Registry) — a TypeScript-first, security-reviewed package registry
deno compile — bundle your app to a single self-contained executable
// Deno 2: security by default
// This script needs --allow-net and --allow-read to run
const response = await fetch("https://api.example.com/data");
const data = await response.json();
// Write to filesystem — requires explicit --allow-write
await Deno.writeTextFile("output.json", JSON.stringify(data, null, 2));
console.log("Done!");
Run with scoped permissions:
deno run \
  --allow-net=api.example.com \
  --allow-write=./output.json \
  main.ts
JSR: A Better npm?
JSR deserves special attention. Unlike npm, every package on JSR:
Must be TypeScript (or provide full type declarations)
Is scored for documentation quality
Is scoped by default (@scope/package)
Supports multiple runtimes (Deno, Node, Bun, Cloudflare Workers)
# Add a JSR package to a Node.js project
npx jsr add @std/datetime
# Add to Deno project
deno add @std/datetime
When to choose Deno:
Security is a top concern (financial services, healthcare)
You want modern TypeScript-first development
You’re deploying to Deno Deploy (edge runtime with zero config)
You want the deno compile single-binary distribution story
Bun: Speed as a Philosophy
Bun’s thesis is that JavaScript tooling is too slow and too fragmented. Instead of a runtime, Bun is a complete JavaScript toolkit in a single binary:
Runtime (JavaScriptCore-based)
Package manager (faster than pnpm in most benchmarks)
Bundler (faster than esbuild for most configs)
Test runner
TypeScript transpiler
HTTP Server Performance
Bun’s Bun.serve() consistently leads benchmarks:
// Bun HTTP server
const server = Bun.serve({
  port: 3000,
  fetch(req) {
    const url = new URL(req.url);
    
    if (url.pathname === "/health") {
      return new Response("OK");
    }
    
    if (url.pathname === "/json") {
      return Response.json({ 
        message: "Hello from Bun!",
        timestamp: Date.now()
      });
    }
    
    return new Response("Not Found", { status: 404 });
  },
});
console.log(`Listening on http://localhost:${server.port}`);
Benchmark results (requests/sec, simple JSON endpoint, Apple M3 Pro):
Runtime
      req/s
    
Bun 1.x
      ~285,000
    
Node.js 24 (uWebSockets)
      ~220,000
    
Deno 2
      ~195,000
    
Node.js 24 (http module)
      ~85,000
    
Bun’s SQLite
import { Database } from "bun:sqlite";
const db = new Database("mydb.sqlite");
const query = db.query("SELECT * FROM users WHERE age > $age");
const users = query.all({ $age: 18 });
When to choose Bun:
Startup time matters (CLI tools, lambdas, edge functions)
You want to drop npm/yarn/pnpm/esbuild/jest in one move
You’re starting fresh with no legacy constraints
Your team values speed of development over ecosystem maturity
Real-World Decision Framework
Building an API/microservice?
Need maximum ecosystem compat → Node.js + Fastify or Hono
Need security isolation → Deno + Oak/Hono
Need maximum throughput → Bun + Elysia
Building a CLI tool?
Distributing as binary → Deno (deno compile) or Bun (bun build --compile)
Publishing to npm → Node.js (widest install base)
Serverless/Edge functions?
Cloudflare Workers → All three work, Deno’s API closest to WinterCG spec
Deno Deploy → Deno obviously
AWS Lambda → Node.js (official runtime), Bun (custom runtime layer)
Monorepo + full-stack?
Next.js/Remix → Node.js or Bun (better compatibility)
Fresh (Deno) → Deno
Interoperability in 2026
The good news: all three runtimes are converging on the WinterCG (Web-interoperable Runtimes Community Group) standard. This means:
fetch, Request, Response — identical across all three
URL, URLSearchParams — standardized
crypto.subtle — identical Web Crypto API
ReadableStream, WritableStream — standard Streams API
Libraries that target WinterCG work on all three runtimes. Hono, for example, is a popular framework that runs identically on Node.js, Deno, Bun, and Cloudflare Workers.
Conclusion
Stop asking which runtime is “best” and start asking which runtime is best for your context:
Node.js 24 is the safe, mature choice with the most ecosystem support
Deno 2 is the right choice when security, TypeScript DX, and modern tooling matter
Bun is the right choice when speed — of runtime and of developer tooling — is the priority
In 2026, you can also mix runtimes per service in a microservices architecture. WinterCG compatibility means sharing business logic across them is increasingly tractable.
References:
Node.js Changelog
Deno 2 Release Notes
Bun Documentation
JSR Registry
WinterCG

Deno 2 vs Node.js vs Bun: Choosing the Right JavaScript Runtime in 2026

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