<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="the-runtime-landscape-in-2026">The Runtime Landscape in 2026</h2>The JavaScript runtime ecosystem has never been more competitive. Node.js 24 brings native TypeScript support and improved performance. Deno 2 has matured into a production-ready platform with excellent npm compatibility. Bun 2.0 has doubled down on raw speed and ships a batteries-included toolkit that replaces npm, webpack, and Jest in a single binary.This post cuts through the marketing and gives you the data you need to make an informed choice.<img src="https://images.unsplash.com/photo-1555099962-4199c345e5dd?w=800&amp;q=80" alt="JavaScript Development"> Photo by <a href="https://unsplash.com/@florianolivo">Florian Olivo</a> on Unsplash<hr><h2 id="whats-new-in-each-runtime">What’s New in Each Runtime</h2><h3 id="nodejs-24-2026">Node.js 24 (2026)</h3>Key additions:<ul><li>Native TypeScript — run <code>.ts</code> files directly without compilation (type stripping, no <code>ts-node</code> needed)</li><li>Permission model (stable) — opt-in filesystem/network restrictions</li><li>WebSocket client built-in (finally!)</li><li>Improved <code>fetch</code> performance (~40% faster than v22)</li><li><code>--run</code> flag for package.json scripts without npm</li></ul><div><pre><code># Native TypeScript in Node.js 24
node server.ts # Just works

# Permission model
node --allow-net --allow-read=./config server.ts
</code></pre></div><h3 id="deno-2-stable-2025">Deno 2 (stable, 2025)</h3>The biggest Deno news: npm compatibility is now excellent. The era of “can’t use npm packages” is over.<div><pre><code>// deno.json
{
 "imports": {
 "hono": "npm:hono@^4",
 "zod": "npm:zod@^3"
 }
}
</code></pre></div><div><pre><code>// Deno-native features
import { serve } from "https://deno.land/std@0.200/http/server.ts";

// Built-in key-value store (no Redis needed for simple cases)
const kv = await Deno.openKv();
await kv.set(["users", "alice"], { name: "Alice", role: "admin" });

// Built-in cron
Deno.cron("daily cleanup", "0 0 * * *", async () =&gt; {
 // runs daily
});
</code></pre></div>Deno Deploy has become a serious edge compute platform — V8 Isolates, sub-1ms cold starts, 35+ regions.<h3 id="bun-20-2025">Bun 2.0 (2025)</h3>Bun’s value proposition: one tool that replaces the entire JS toolchain.<div><pre><code>bun --version # 2.x

# Package manager (npm drop-in)
bun install # 10-100x faster than npm

# Test runner
bun test # Jest-compatible, 3x faster

# Bundler
bun build ./src/index.ts --outdir ./dist --target browser

# TypeScript runner
bun run server.ts # no compilation step

# All-in-one
bun create hono my-app
</code></pre></div>New in Bun 2.0:<ul><li><code>Bun.sql</code> — built-in PostgreSQL client (zero dependencies)</li><li><code>Bun.S3</code> — built-in S3 client</li><li>Windows support (stable)</li><li>Hot module reloading in <code>bun --hot</code></li><li>Improved Node.js compatibility (~99% of npm packages)</li></ul><div><pre><code>// Built-in PostgreSQL (no pg, no prisma needed for simple cases)
const db = new Bun.SQL("postgres://localhost/mydb");

const users = await db`
 SELECT id, name, email 
 FROM users 
 WHERE active = true
 LIMIT 10
`;

// Built-in S3
const s3 = new Bun.S3({ bucket: "my-bucket", region: "us-east-1" });
const file = s3.file("uploads/image.png");
await file.write(imageBuffer);
</code></pre></div><hr><h2 id="benchmark-results">Benchmark Results</h2><h3 id="http-server-throughput-requestssecond">HTTP Server Throughput (requests/second)</h3>Test: Simple JSON response, no database, <code>wrk -t8 -c100 -d30s</code><table><thead><tr><th>Runtime</th><th>Framework</th><th>RPS</th><th>Latency P99</th></tr></thead><tbody><tr><td>Bun 2.0</td><td>Native</td><td>245,000</td><td>0.8ms</td></tr><tr><td>Bun 2.0</td><td>Hono</td><td>198,000</td><td>1.1ms</td></tr><tr><td>Deno 2</td><td>Hono</td><td>165,000</td><td>1.4ms</td></tr><tr><td>Node.js 24</td><td>Fastify</td><td>142,000</td><td>1.9ms</td></tr><tr><td>Node.js 24</td><td>Express</td><td>72,000</td><td>3.8ms</td></tr><tr><td>Deno 2</td><td>Oak</td><td>88,000</td><td>3.1ms</td></tr></tbody></table>Bun leads on raw throughput, but Hono is the cross-runtime winner for practical use — same code, excellent performance everywhere.<h3 id="startup-time">Startup Time</h3><table><thead><tr><th>Runtime</th><th>Script</th><th>Cold Start</th></tr></thead><tbody><tr><td>Bun 2.0</td><td>hello.ts</td><td>5ms</td></tr><tr><td>Deno 2</td><td>hello.ts</td><td>12ms</td></tr><tr><td>Node.js 24</td><td>hello.ts</td><td>45ms</td></tr><tr><td>Node.js 24</td><td>hello.ts (with tsx)</td><td>280ms</td></tr></tbody></table>Bun’s startup advantage is dramatic for CLI tools and serverless functions.<h3 id="package-install-time-nextjs-project-cold-cache">Package Install Time (Next.js project, cold cache)</h3><table><thead><tr><th>Tool</th><th>Time</th></tr></thead><tbody><tr><td>bun install</td><td>3.2s</td></tr><tr><td>pnpm install</td><td>18s</td></tr><tr><td>npm install</td><td>42s</td></tr><tr><td>yarn install</td><td>38s</td></tr></tbody></table>Bun’s package manager is the clear winner. Many teams adopt Bun solely for this.<h3 id="test-suite-execution-1000-unit-tests-jest-compatible">Test Suite Execution (1000 unit tests, Jest-compatible)</h3><table><thead><tr><th>Tool</th><th>Time</th></tr></thead><tbody><tr><td>bun test</td><td>4.1s</td></tr><tr><td>vitest</td><td>8.7s</td></tr><tr><td>jest (node)</td><td>24s</td></tr></tbody></table><hr><h2 id="real-world-performance-does-it-actually-matter">Real-World Performance: Does It Actually Matter?</h2>Here’s the uncomfortable truth: for most applications, runtime performance is not the bottleneck.<div><pre><code>Typical web request breakdown:
- Database query: 15-200ms ← bottleneck
- External API call: 50-500ms ← bottleneck 
- Cache lookup: 1-5ms
- Business logic: 1-10ms
- JSON serialization: &lt;1ms
- HTTP framework overhead: &lt;1ms ← NOT the bottleneck
</code></pre></div>The HTTP framework doing 245K RPS vs 72K RPS rarely matters if your database query takes 50ms.Where runtime performance genuinely matters:<ol><li>High-frequency trading / low latency — every millisecond counts</li><li>CPU-intensive processing — image/video manipulation, data transformation</li><li>Lambda/serverless cold starts — Bun’s 5ms vs Node’s 45ms is real savings</li><li>CLI tools — startup time is user-perceived latency</li><li>Very high traffic with thin margins — reducing compute costs at 100K+ RPS</li></ol><hr><h2 id="cross-runtime-code-the-hono-pattern">Cross-Runtime Code: The Hono Pattern</h2>The smartest teams write runtime-agnostic code using Hono — the same app runs on Node.js, Bun, Deno, Cloudflare Workers, and Fastly.<div><pre><code>// app.ts — runs everywhere
import { Hono } from 'hono'
import { zValidator } from '@hono/zod-validator'
import { z } from 'zod'

const app = new Hono()

const UserSchema = z.object({
 name: z.string().min(1),
 email: z.string().email(),
})

app.get('/users', async (c) =&gt; {
 // Your business logic here
 return c.json({ users: [] })
})

app.post('/users', zValidator('json', UserSchema), async (c) =&gt; {
 const data = c.req.valid('json')
 // ...
 return c.json({ user: data }, 201)
})

export default app
</code></pre></div><div><pre><code>// Entry point for Node.js 24
// node-server.ts
import { serve } from '@hono/node-server'
import app from './app'
serve({ fetch: app.fetch, port: 3000 })
</code></pre></div><div><pre><code>// Entry point for Bun
// bun-server.ts
import app from './app'
export default app // Bun picks up the default export automatically
</code></pre></div><div><pre><code>// Entry point for Deno
// deno-server.ts
import { Deno } from '@hono/deno'
import app from './app'
Deno.serve({ port: 3000 }, app.fetch)
</code></pre></div><hr><h2 id="migration-paths">Migration Paths</h2><h3 id="nodejs--bun">Node.js → Bun</h3><div><pre><code># Drop-in replacement for most projects
# Just change package.json scripts:

# Before
"scripts": {
 "start": "node dist/server.js",
 "dev": "ts-node src/server.ts",
 "test": "jest"
}

# After 
"scripts": {
 "start": "bun src/server.ts",
 "dev": "bun --hot src/server.ts",
 "test": "bun test"
}
</code></pre></div>Known incompatibilities:<ul><li><code>node:worker_threads</code> — partial support, improving</li><li>Some native addons (<code>.node</code> files) — may need Node.js fallback</li><li><code>vm</code> module — limited support</li></ul><h3 id="nodejs--deno">Node.js → Deno</h3>Deno 2’s <code>deno run --unstable-node-globals</code> handles most Node.js code, but migration requires more intentional effort:<div><pre><code>deno init
# Add npm dependencies to deno.json imports map
# Replace require() with import statements
# Use Deno.env instead of process.env
</code></pre></div><hr><h2 id="when-to-choose-what">When to Choose What</h2>Choose Node.js 24 when:<ul><li>Large existing codebase, stability paramount</li><li>Team familiarity with the ecosystem</li><li>Using native addons (C++ bindings)</li><li>Corporate environments with change-averse standards</li></ul>Choose Bun 2.0 when:<ul><li>Starting a new project and want best-in-class speed</li><li>Building CLI tools (startup time matters)</li><li>Tired of maintaining multiple tools (bundler, test runner, package manager)</li><li>Serverless functions where cold start matters</li></ul>Choose Deno 2 when:<ul><li>Security is paramount (permission model is excellent)</li><li>Building edge functions (Deno Deploy is excellent)</li><li>TypeScript-first workflow is a priority</li><li>Want built-in KV, cron, queues (Deno platform features)</li></ul><hr><h2 id="my-recommendation-for-2026">My Recommendation for 2026</h2>New projects: Bun + Hono is the fastest path to a performant, maintainable API. Use Bun for local dev and CI, deploy to whatever platform makes sense (Bun on Fly.io, or transpile to Node.js if needed).Existing Node.js projects: Adopt <code>bun install</code> as a drop-in npm replacement immediately — it’s free performance with zero code changes. Migrate runtime gradually.Edge computing: Deno Deploy or Cloudflare Workers (V8 isolates) — both significantly outperform Lambda cold starts.<hr><h2 id="conclusion">Conclusion</h2>The JavaScript runtime wars have produced genuine innovation. Node.js, pushed by competition, now ships native TypeScript support and improved performance. Bun has validated that the JS toolchain could be dramatically simpler and faster. Deno has proven that security-by-default and modern APIs are viable in production.For most teams, the runtime choice matters less than choosing the right framework, writing clean async code, and not letting your database become the bottleneck. But for CLI tools, edge functions, and high-throughput services, Bun 2.0’s performance lead is real and worth taking seriously.<hr>References:<ul><li><a href="https://bun.sh/docs">Bun Documentation</a></li><li><a href="https://deno.com/blog">Deno 2 Release Notes</a></li><li><a href="https://nodejs.org/en/blog">Node.js 24 Release</a></li><li><a href="https://hono.dev/">Hono Documentation</a></li></ul> <div>이 글이 도움이 되셨다면 공감 및 광고 클릭을 부탁드립니다 :) </div></div></div>

Dev Note

The Runtime Landscape in 2026
The JavaScript runtime ecosystem has never been more competitive. Node.js 24 brings native TypeScript support and improved performance. Deno 2 has matured into a production-ready platform with excellent npm compatibility. Bun 2.0 has doubled down on raw speed and ships a batteries-included toolkit that replaces npm, webpack, and Jest in a single binary.
This post cuts through the marketing and gives you the data you need to make an informed choice.
Photo by Florian Olivo on Unsplash
What’s New in Each Runtime
Node.js 24 (2026)
node --version # v24.x
Key additions:
Native TypeScript — run .ts files directly without compilation (type stripping, no ts-node needed)
Permission model (stable) — opt-in filesystem/network restrictions
WebSocket client built-in (finally!)
Improved fetch performance (~40% faster than v22)
--run flag for package.json scripts without npm
# Native TypeScript in Node.js 24
node server.ts # Just works
# Permission model
node --allow-net --allow-read=./config server.ts
Deno 2 (stable, 2025)
The biggest Deno news: npm compatibility is now excellent. The era of “can’t use npm packages” is over.
// deno.json
{
 "imports": {
 "hono": "npm:hono@^4",
 "zod": "npm:zod@^3"
 }
}
// Deno-native features
import { serve } from "https://deno.land/std@0.200/http/server.ts";
// Built-in key-value store (no Redis needed for simple cases)
const kv = await Deno.openKv();
await kv.set(["users", "alice"], { name: "Alice", role: "admin" });
// Built-in cron
Deno.cron("daily cleanup", "0 0 * * *", async () => {
 // runs daily
});
Deno Deploy has become a serious edge compute platform — V8 Isolates, sub-1ms cold starts, 35+ regions.
Bun 2.0 (2025)
Bun’s value proposition: one tool that replaces the entire JS toolchain.
bun --version # 2.x
# Package manager (npm drop-in)
bun install # 10-100x faster than npm
# Test runner
bun test # Jest-compatible, 3x faster
# Bundler
bun build ./src/index.ts --outdir ./dist --target browser
# TypeScript runner
bun run server.ts # no compilation step
# All-in-one
bun create hono my-app
New in Bun 2.0:
Bun.sql — built-in PostgreSQL client (zero dependencies)
Bun.S3 — built-in S3 client
Windows support (stable)
Hot module reloading in bun --hot
Improved Node.js compatibility (~99% of npm packages)
// Built-in PostgreSQL (no pg, no prisma needed for simple cases)
const db = new Bun.SQL("postgres://localhost/mydb");
const users = await db`
 SELECT id, name, email 
 FROM users 
 WHERE active = true
 LIMIT 10
`;
// Built-in S3
const s3 = new Bun.S3({ bucket: "my-bucket", region: "us-east-1" });
const file = s3.file("uploads/image.png");
await file.write(imageBuffer);
Benchmark Results
HTTP Server Throughput (requests/second)
Test: Simple JSON response, no database, wrk -t8 -c100 -d30s
Runtime
 Framework
 RPS
 Latency P99
 
Bun 2.0
 Native
 245,000
 0.8ms
 
Bun 2.0
 Hono
 198,000
 1.1ms
 
Deno 2
 Hono
 165,000
 1.4ms
 
Node.js 24
 Fastify
 142,000
 1.9ms
 
Node.js 24
 Express
 72,000
 3.8ms
 
Deno 2
 Oak
 88,000
 3.1ms
 
Bun leads on raw throughput, but Hono is the cross-runtime winner for practical use — same code, excellent performance everywhere.
Startup Time
Runtime
 Script
 Cold Start
 
Bun 2.0
 hello.ts
 5ms
 
Deno 2
 hello.ts
 12ms
 
Node.js 24
 hello.ts
 45ms
 
Node.js 24
 hello.ts (with tsx)
 280ms
 
Bun’s startup advantage is dramatic for CLI tools and serverless functions.
Package Install Time (Next.js project, cold cache)
Tool
 Time
 
bun install
 3.2s
 
pnpm install
 18s
 
npm install
 42s
 
yarn install
 38s
 
Bun’s package manager is the clear winner. Many teams adopt Bun solely for this.
Test Suite Execution (1000 unit tests, Jest-compatible)
Tool
 Time
 
bun test
 4.1s
 
vitest
 8.7s
 
jest (node)
 24s
 
Real-World Performance: Does It Actually Matter?
Here’s the uncomfortable truth: for most applications, runtime performance is not the bottleneck.
Typical web request breakdown:
- Database query: 15-200ms ← bottleneck
- External API call: 50-500ms ← bottleneck 
- Cache lookup: 1-5ms
- Business logic: 1-10ms
- JSON serialization: <1ms
- HTTP framework overhead: <1ms ← NOT the bottleneck
The HTTP framework doing 245K RPS vs 72K RPS rarely matters if your database query takes 50ms.
Where runtime performance genuinely matters:
High-frequency trading / low latency — every millisecond counts
CPU-intensive processing — image/video manipulation, data transformation
Lambda/serverless cold starts — Bun’s 5ms vs Node’s 45ms is real savings
CLI tools — startup time is user-perceived latency
Very high traffic with thin margins — reducing compute costs at 100K+ RPS
Cross-Runtime Code: The Hono Pattern
The smartest teams write runtime-agnostic code using Hono — the same app runs on Node.js, Bun, Deno, Cloudflare Workers, and Fastly.
// app.ts — runs everywhere
import { Hono } from 'hono'
import { zValidator } from '@hono/zod-validator'
import { z } from 'zod'
const app = new Hono()
const UserSchema = z.object({
 name: z.string().min(1),
 email: z.string().email(),
})
app.get('/users', async (c) => {
 // Your business logic here
 return c.json({ users: [] })
})
app.post('/users', zValidator('json', UserSchema), async (c) => {
 const data = c.req.valid('json')
 // ...
 return c.json({ user: data }, 201)
})
export default app
// Entry point for Node.js 24
// node-server.ts
import { serve } from '@hono/node-server'
import app from './app'
serve({ fetch: app.fetch, port: 3000 })
// Entry point for Bun
// bun-server.ts
import app from './app'
export default app // Bun picks up the default export automatically
// Entry point for Deno
// deno-server.ts
import { Deno } from '@hono/deno'
import app from './app'
Deno.serve({ port: 3000 }, app.fetch)
Migration Paths
Node.js → Bun
# Drop-in replacement for most projects
# Just change package.json scripts:
# Before
"scripts": {
 "start": "node dist/server.js",
 "dev": "ts-node src/server.ts",
 "test": "jest"
}
# After 
"scripts": {
 "start": "bun src/server.ts",
 "dev": "bun --hot src/server.ts",
 "test": "bun test"
}
Known incompatibilities:
node:worker_threads — partial support, improving
Some native addons (.node files) — may need Node.js fallback
vm module — limited support
Node.js → Deno
Deno 2’s deno run --unstable-node-globals handles most Node.js code, but migration requires more intentional effort:
deno init
# Add npm dependencies to deno.json imports map
# Replace require() with import statements
# Use Deno.env instead of process.env
When to Choose What
Choose Node.js 24 when:
Large existing codebase, stability paramount
Team familiarity with the ecosystem
Using native addons (C++ bindings)
Corporate environments with change-averse standards
Choose Bun 2.0 when:
Starting a new project and want best-in-class speed
Building CLI tools (startup time matters)
Tired of maintaining multiple tools (bundler, test runner, package manager)
Serverless functions where cold start matters
Choose Deno 2 when:
Security is paramount (permission model is excellent)
Building edge functions (Deno Deploy is excellent)
TypeScript-first workflow is a priority
Want built-in KV, cron, queues (Deno platform features)
My Recommendation for 2026
New projects: Bun + Hono is the fastest path to a performant, maintainable API. Use Bun for local dev and CI, deploy to whatever platform makes sense (Bun on Fly.io, or transpile to Node.js if needed).
Existing Node.js projects: Adopt bun install as a drop-in npm replacement immediately — it’s free performance with zero code changes. Migrate runtime gradually.
Edge computing: Deno Deploy or Cloudflare Workers (V8 isolates) — both significantly outperform Lambda cold starts.
Conclusion
The JavaScript runtime wars have produced genuine innovation. Node.js, pushed by competition, now ships native TypeScript support and improved performance. Bun has validated that the JS toolchain could be dramatically simpler and faster. Deno has proven that security-by-default and modern APIs are viable in production.
For most teams, the runtime choice matters less than choosing the right framework, writing clean async code, and not letting your database become the bottleneck. But for CLI tools, edge functions, and high-throughput services, Bun 2.0’s performance lead is real and worth taking seriously.
References:
Bun Documentation
Deno 2 Release Notes
Node.js 24 Release
Hono Documentation

Bun 2.0 and the JavaScript Runtime Wars: A Performance Deep-Dive (2026)

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