The State of JavaScript Runtimes in 2026
Two years ago, choosing a JavaScript runtime meant choosing Node.js. Today you have three serious options: Node.js 22, Bun 1.2, and Deno 2. This guide focuses on the two most common choices for new backend projects in 2026: Bun 1.2 and Node.js 22.
What Bun 1.2 Adds
Bun 1.2 is a major compatibility and productivity release:
- Native S3 and R2 API —
Bun.s3andBun.r2for object storage without the AWS SDK - 90% Node.js API compatibility — virtually all npm packages work now
- Hot module reloading —
bun --hotfor server-side hot reload - Node.js test runner compatibility —
node:testmodule supported - Windows stability — first fully stable Windows release
// Native S3 in Bun 1.2 — no AWS SDK needed
const file = Bun.s3.file("uploads/photo.png");
await file.write(imageBuffer, { type: "image/png" });
const url = file.presign({ expiresIn: 3600 });
Performance Benchmarks
These numbers are from independent benchmarks on identical hardware (M2 Pro, 16GB RAM):
| Workload | Bun 1.2 | Node.js 22 | Difference | |----------|---------|------------|------------| | HTTP server (req/s) | 130,000 | 35,000 | 3.7x faster | | File I/O (MB/s) | 9,200 | 3,100 | 3x faster | | Startup time | 8ms | 45ms | 5.6x faster | | JSON parse (ops/s) | 850,000 | 420,000 | 2x faster | | SQLite (ops/s) | 680,000 | 210,000* | 3.2x faster |
*Node.js 22 now includes a built-in SQLite module (node:sqlite), though Bun's is faster.
bun --hot vs nodemon
Bun's native hot reload is faster and does not require a separate package:
# Bun — built in
bun --hot server.ts
# Node.js — requires nodemon or tsx --watch
npx nodemon --exec ts-node server.ts
With --hot, Bun reloads only the changed module and its dependents, preserving open connections. This is closer to Vite HMR than a full process restart.
Node.js 22: What's New
Node.js 22 is not standing still:
// Built-in SQLite — no better-sqlite3 needed
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");
require(esm) is now stable — you can require() ES modules from CommonJS code without async imports. This unblocks a long-standing ecosystem problem.
Node.js 22 also gets permission model improvements (experimental --experimental-permission) and a native test runner that has matured significantly.
When to Pick Bun
- New API services where performance matters
- Scripts and CLI tools (startup time is critical)
- Projects that need native S3/R2 without the AWS SDK
- Teams comfortable on the bleeding edge
When to Pick Node.js
- Existing codebases with complex webpack/PostCSS build pipelines
- Projects requiring 100% ecosystem compatibility (rare edge cases still hit Bun)
- Enterprise environments with Node.js as the supported runtime
- When deploying to platforms that only support Node.js officially
Install and Try
# Install Bun
curl -fsSL https://bun.sh/install | bash
# Run a Node.js project with Bun (usually zero config)
bun install
bun run start
References: Bun 1.2 · Node.js 22
