Bun 1.2 vs Deno 2 vs Node.js 22: Performance, Compatibility & Ecosystem 2026

The JavaScript runtime landscape has matured significantly. Bun 1.2 shipped Windows support and a rewritten package manager. Deno 2 closed the npm compatibility gap that held back adoption. Node.js 22 brought native TypeScript stripping and a built-in test runner out of experimental status. In 2026, choosing a runtime is a real architectural decision with measurable tradeoffs. Here is the breakdown.

Performance Benchmarks

Numbers from independent benchmarks (hardware: AMD Ryzen 9 7950X, 64GB RAM, NVMe SSD, Ubuntu 22.04 LTS).

Benchmark	Bun 1.2	Deno 2.0	Node.js 22
Cold start (hello world)	~7ms	~25ms	~45ms
npm install (fresh, 100 deps)	~2.1s	~4.8s	~8.2s
HTTP throughput (req/s, simple JSON)	~210,000	~185,000	~160,000
TypeScript compilation (large project)	~0.8s (transpile only)	~1.2s (transpile only)	~3.4s (tsc)
sqlite query (10k rows)	~12ms (built-in)	~18ms (via npm)	~22ms (better-sqlite3)
Memory usage (idle HTTP server)	~28MB	~35MB	~42MB

Key takeaways:

• Bun leads across startup, HTTP throughput, and package installation speed
• Deno 2 is competitive with Node on throughput and beats it on startup
• Node.js 22 trails on raw performance but the gap is smaller than it was in 2023

TypeScript Support

All three runtimes execute TypeScript without a separate compilation step, but the implementations differ:

Bun: Uses a custom TypeScript transpiler. Strips types at parse time — no type checking. Fastest execution path. Run .ts files directly with bun run script.ts.

Deno: Has always treated TypeScript as a first-class language. Runs .ts files natively, includes deno check for type checking, and supports deno compile to produce standalone executables.

Node.js 22: Added --experimental-strip-types (graduated to stable in 22.x). Like Bun, it strips types without checking. For full type checking, tsc is still required separately.

# All three: run a TypeScript file directly
bun run server.ts
deno run server.ts
node --input-type=ts server.ts  # Node 22+

For teams that need runtime-level type checking, Deno is the only option. For teams where type checking happens in CI via tsc, all three are equivalent.

npm Compatibility

This was the critical adoption barrier for both Bun and Deno, and both have largely closed the gap:

Compatibility	Bun 1.2	Deno 2.0	Node.js 22
npm packages	~99% compatible	~95% compatible	100% (reference)
node_modules	Yes	Yes (optional)	Yes
package.json	Yes	Yes	Yes
CommonJS (require)	Yes	Yes (interop layer)	Yes
Native addons (.node)	Yes (napi-rs)	Limited	Yes
Workspace support	Yes	Yes	Yes

Deno 2 npm compatibility note: Deno now supports npm: specifiers and package.json. Most packages work, but packages that rely heavily on undocumented Node internals or native bindings may still fail.

// Deno 2: import from npm
import express from "npm:express@4";
import { z } from "npm:zod";

// Or use package.json as usual
import { z } from "zod"; // with deno.json imports map

Ecosystem Maturity

Node.js has a 15-year head start and it shows:

Factor	Bun	Deno	Node.js
Years in production	3	6	15+
Package ecosystem	npm (full)	npm + deno.land/x	npm (full)
Community size	Growing fast	Established	Massive
Framework support	Good	Good	Excellent
Cloud provider support	Growing	Good	Excellent
Docker images	Official	Official	Official
AWS Lambda	Yes (custom runtime)	Yes (custom runtime)	Official support
Vercel Edge	Yes	Yes	Yes

If you’re deploying to AWS Lambda with standard runtimes or relying on less-common npm packages with native bindings, Node.js is the lower-risk choice. For greenfield projects, both Bun and Deno are production-ready.

Best Use Cases Per Runtime

Bun 1.2

Best choice when raw performance matters most:

# Bun's built-in test runner (Jest-compatible)
bun test

# Bun's package manager (drop-in npm replacement)
bun install
bun add zod

# Built-in SQLite — no dependency needed
import { Database } from "bun:sqlite";
const db = new Database("app.db");
const rows = db.query("SELECT * FROM users WHERE active = ?").all(1);

Ideal for:

• API servers where startup time and throughput matter (serverless, edge)
• Projects that spend significant time on npm install in CI
• Monorepos that benefit from Bun’s workspace-aware package manager
• Scripts and CLIs where startup latency is noticeable

Deno 2.0

Best choice when security, TypeScript-first, and a batteries-included runtime are priorities:

// Deno: explicit permissions model
// deno run --allow-net --allow-read server.ts

// Built-in HTTP server (no express needed)
Deno.serve({ port: 8080 }, (req) => {
  return new Response("Hello, World!");
});

// Built-in key-value store (Deno Deploy)
const kv = await Deno.openKv();
await kv.set(["users", "alice"], { name: "Alice", role: "admin" });

Ideal for:

• Security-sensitive applications (permissions model prevents supply chain attacks)
• Serverless on Deno Deploy (global edge, built-in KV, no config)
• Projects where built-in tooling (formatter, linter, test runner) simplifies the stack
• Teams that want TypeScript checking at runtime, not just build time

Node.js 22

Best choice for maximum ecosystem compatibility and lowest adoption risk:

// Node 22: built-in test runner (no jest/vitest needed)
import { test, describe } from "node:test";
import assert from "node:assert";

describe("User service", () => {
  test("creates a user", async () => {
    const user = await createUser({ name: "Alice" });
    assert.strictEqual(user.name, "Alice");
  });
});

// Native TypeScript stripping (no tsc needed at runtime)
// node --experimental-strip-types server.ts

Ideal for:

• Existing projects — migration cost to Bun/Deno rarely justifies the performance gain
• Enterprise teams where support contracts and ecosystem breadth matter
• Applications with AWS Lambda, GCP Cloud Functions, or Azure Functions official runtime support
• Any project with native addon dependencies

Migration Considerations

Moving from Node to Bun: Most projects migrate with minimal changes. Run bun install instead of npm install, then bun run instead of node. Watch for edge cases around __dirname (available in Bun) and native addon binaries.

Moving from Node to Deno: Requires more work. Update import paths to use npm: specifiers or a package.json import map. Audit code for Node-specific APIs without Deno equivalents. Worth it for new projects starting fresh.

Keeping Node: Perfectly valid in 2026. The built-in test runner, native TypeScript stripping, and improved ESM support have closed many of the quality-of-life gaps. If your project is running smoothly on Node, the performance gains from migrating are unlikely to justify the risk.

The Bottom Line

• Maximum performance / CI speed: Bun
• Security-first / batteries included: Deno
• Lowest friction / existing projects: Node.js

The runtime choice matters less than code quality, architecture, and database design. Pick the one with the best fit for your team’s constraints and ship the product.