Bun vs Node.js vs Deno: Which JavaScript Runtime to Use in 2026?

2026 TL;DR#

• Node.js — still the production default. Largest ecosystem, most battle-tested.
• Bun — production-ready for HTTP servers, build tooling, fast script runs. ~2-3× faster than Node.
• Deno 2 — has a Node-compat layer, better security defaults, but smaller adoption.

Cold start + HTTP throughput#

Indicative figures showing rough order of magnitude; real results depend on setup, workload, and version.

Cold start (single function)#

Bun — production-ready for what?#

Yes, use Bun for:

• HTTP servers (Hono, Elysia)
• Static-site builders (Astro, Vite — Bun as package manager + bundler)
• Test runner (bun test) — 10× faster than Jest
• Utility scripts (bun run script.ts — TypeScript native, no transpile)
• Bun.serve for file delivery / proxy

Avoid Bun for:

• Workloads depending on native modules (canvas, older sharp, some C++ bindings).
• Long-running servers > 1 week — edge-case memory leaks reported.
• Complex tooling with many non-standard node_modules deps.

Deno 2 — sweet spot#

• Secure defaults — no FS/network access without explicit --allow-read.
• Built-in TypeScript with no config.
• Web standard APIs (Fetch, Request, Response) — code portable to Cloudflare Workers / browsers.
• Mature Node compat layer in Deno 2.
• JSR registry as a curated NPM alternative.

But adoption < Bun. Hiring Deno engineers in Indonesia is very hard.

Node.js — why still dominant#

• Largest ecosystem, every library exists.
• Production-tested in hundreds of thousands of deployments.
• Stable LTS, predictable.
• Easiest hire in Indonesia.

Decision matrix#

Use case	Recommendation
Production SaaS in Indonesia	Node.js 22 (TS + Hono / Express + ts-node-esm)
HTTP-heavy microservice	Bun + Hono (if the team is open to experimenting)
Edge functions (Cloudflare Workers, Deno Deploy)	Deno (portable web standard APIs)
CLI / build tooling	Bun (fastest)
Test runner	Bun test or Vitest on Node
Lambda / serverless	Bun layer or Node 22

What Lancartech uses#

• Client production apps → Node.js 22 (most reliable + ecosystem)
• Internal CLI scripts → Bun (fast, TS native)
• Test runner in new projects → Bun test
• Edge workers (on Cloudflare) → Deno-style code with Hono

Migrating Node → Bun#

A standard Node.js project usually runs on Bun directly:

# instead of: npm install
bun install

# instead of: node index.js
bun run index.js

# instead of: jest
bun test

Try a staging branch first, monitor metrics. Bun is typically 2-3× faster for install + run in many cases.

Runtime-stack consult.