Runtimes · Updated 2026-05-24

Bun vs Node

Node is still the safe default for production: 16 years of operational knowledge, every cloud platform supports it, every npm package targets it. Bun is faster (JavaScriptCore + Zig + native APIs) and bundles its own package manager, test runner, and TS compiler — but its ecosystem compatibility, while excellent, is not 100%. Use Bun for new projects and scripts; keep Node for things in production that work.

PLATE — JS TOOLCHAIN SHAPEBUN · ALL-IN-ONEbunruntime · JavaScriptCorepackage manager · installtest runner · testbundler · buildnative TS execution.env, SQL, HTTPone binary · ~80 MBvsNODE · PICK YOUR TOOLSnoderuntime · V8npm/pnpmtsx/ts-nodevitestjestesbuildvitedotenvruntime + curated toolchainONE BINARY · CURATED ECOSYSTEM
Bun
All-in-one JavaScript runtime + toolchain. Fast, drop-in for Node.
Since
2022
By
Oven
License
MIT
bun.sh ↗
Node.js
The reference JavaScript runtime. V8, libuv, npm-native.
Since
2009
By
OpenJS Foundation
License
MIT
nodejs.org ↗

Both run JavaScript and TypeScript on the server. Node uses V8 (Chrome's engine) on top of libuv. Bun uses JavaScriptCore (Safari's engine) written in Zig with native implementations of common APIs. Bun is a runtime, package manager, test runner, and bundler in one binary. Node is a runtime with a thriving ecosystem of separate tools (npm/pnpm, tsx, esbuild, vitest). The Bun bet is that "fewer tools is better"; the Node bet is that "many tools, one each picked well" is better.

Quick takes

If you're…

  • You're running production today on Node 20+ Node Don't change what works. Migrating to Bun is a project, not a flag flip.
  • You're writing a quick script or CLI tool Bun Bun executes TypeScript directly, no build step. Faster startup.
  • You want the absolute best npm compatibility Node Node is the reference. Bun is close but not 100%.
  • You're bottlenecked on cold start (Lambda, edge functions) Bun Bun starts measurably faster — important for serverless cold paths.
  • You need long-term support and predictable releases Node Node has scheduled LTS releases (active + maintenance). Bun is faster-moving but less predictable.
  • You're consolidating package manager + runtime + bundler Bun Bun replaces all three. One install.
  • You're building on AWS Lambda or Vercel Edge Node Node has first-party support; Bun support is improving but still limited.
  • You're running benchmarks for fun and want bragging rights Bun Bun wins most benchmark scenarios. Real-world matters more, but the speed is real.
Decision wizard

A few questions, a verdict.

Q1

New project or existing codebase?

Q2

Deployment target?

Q3

How important is npm compatibility?

Q4

Tolerance for "newer, less mature"?

At a glance

The scorecard.

Dimension
Bun
Node
Edge
JavaScriptCore + Zig
V8 (mature, profileable)
depends
~30 ms cold start
~120 ms cold start (improving)
Bun
~95% — improving fast
100% reference compatibility
Node
Package mgr + test + bundler in box
Runtime only; pick your toolchain
Bun
Native TS execution
TS stripping (22.6+, experimental)
Bun
Faster on most benchmarks
Slower but mature + predictable
Bun
Production-grade but new
16 years, deeply mature
Node
Release model ecosystem
Frequent, no formal LTS
Scheduled LTS, predictable
Node
In depth

Dimension by dimension.

core

JavaScript engine

depends
Bun

JavaScriptCore (Safari's engine), written into Bun via Zig. Different optimisation profile than V8 — often faster on startup and string-heavy work.

Node

V8 (Chrome's engine), the most widely-tuned JS engine in the world. Predictable performance, mature profiling tools.

core

Cold start time

edge: Bun
Bun

Significantly faster cold start. ~30ms for a simple HTTP server vs ~120ms for Node. Matters for serverless.

Node

Slower cold start, but startup time has improved with snapshot-based init (Node 22+).

core

npm compatibility

edge: Node
Bun

Excellent — about 95%+ of npm packages work without modification. Native modules using N-API mostly work; some edge cases break.

Node

The reference. Every npm package targets Node first.

features

Built-in toolchain

edge: Bun
Bun

Package manager, test runner, bundler, .env loader, SQL driver (Bun.sql), HTTP server — all in the runtime binary.

Node

Just the runtime. Pair with npm/pnpm/yarn for packages, vitest/jest for tests, esbuild/Vite for bundling, dotenv for env, etc.

features

TypeScript support

edge: Bun
Bun

Native TypeScript execution. `bun run foo.ts` Just Works. No transpile step in dev.

Node

Type stripping support since Node 22.6 (experimental). Most teams still use tsx, ts-node, or compile-then-run.

core

Runtime performance

edge: Bun
Bun

Faster on most benchmarks (HTTP server, JSON parsing, package install). Particularly strong on workloads with lots of small files or short-lived processes.

Node

Slower on benchmarks, but consistent and well-understood. V8 optimisation has 16 years of operational experience behind it.

ops

Production maturity

edge: Node
Bun

Growing fast. Companies report production use but it's still measured in months, not years. Bug-fix turnaround is excellent.

Node

16 years in production. Every cloud platform, every PaaS, every observability tool supports it natively.

ecosystem

Release model

edge: Node
Bun

Frequent releases. No formal LTS yet. Versioning is semver but the velocity is closer to a Linux distro than a runtime.

Node

Scheduled LTS releases (active for 18 months, maintenance for 12). Predictable upgrade cycle.

Benchmark

HTTP server throughput, 64 concurrent connections

wrk benchmark, 30 seconds, 64 concurrent connections, simple JSON response. Both runtimes serving the same handler on Linux 6.8, c7i.2xlarge. Numbers from Bun's public benchmark suite + community retests on Node 22 LTS.

Metric
Bun
Node
Better
Requests/sec (hello world)
Bun's native HTTP server outpaces Node http.
148k rps
72k rps
Bun
p99 latency
1.8 ms
4.2 ms
Bun
Cold start (HTTP server)
Matters for AWS Lambda, Vercel Functions.
32 ms
118 ms
Bun
package install (Next.js project)
Bun install is the fastest npm install you can use.
2.4 s
18 s
Bun
Memory at idle
Node uses less; Bun pays for built-in tools.
38 MB
28 MB
Node

Source: Bun official benchmarks + community retest ↗

When to pick neither

A different shape of problem.

  • Deno
    You want secure-by-default, web-standard APIs, and a clean break from Node compatibility
  • tsx
    You want TypeScript-in-Node without leaving Node
  • esbuild
    Pure bundler, no runtime; for build pipelines
  • pnpm
    Node + a faster package manager; smallest disk footprint
  • Cloudflare Workers runtime
    V8 isolates, edge-only, no Node compatibility (mostly)
  • Hermes
    React Native; AOT-compiled JS for mobile
Situational picks

For specific cases.

New CLI tool or script

Bun

Native TS, fast startup, one binary. Lower friction than Node + tsx + tsconfig.

Production API server on EC2 or Kubernetes

Node

Stability and operational maturity matter more than benchmark wins. Reconsider in a year.

AWS Lambda function with cold-start sensitivity

Node

Lambda supports Node officially. Bun on Lambda works via custom runtime but it's not first-class yet.

Internal tool / dashboard, small team, willing to live on the edge

Bun

Faster install, native TS, built-in toolchain. The DX gains compound.

Replacing your package manager only

Bun

`bun install` is dramatically faster than npm/pnpm. Works inside Node-runtime projects.

Edge / serverless with V8 isolates

Cloudflare Workers runtime or Deno Deploy

Both Bun and Node start cold. For sub-millisecond startup at the edge, V8-isolate-based runtimes are the answer.

Sources

Primary material.

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