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Bun Shell vs zx: Writing Shell Scripts in JavaScript 2026

·PkgPulse Team
bunzxshell-scriptingjavascripttypescript2026

TL;DR

Use zx for portable scripts that run on Node.js; use Bun Shell for maximum performance and native TypeScript in Bun projects. Bun Shell ($) is ~10x faster than zx for subprocess invocations due to no overhead from spawning Node.js or separate interpreters. zx is more mature (2M+ downloads/week), has a richer utility library (chalk, fetch, YAML parsing), and runs anywhere Node.js does. Bun Shell is the right choice in 2026 if you're already on Bun.

Key Takeaways

  • zx: 2M downloads/week, Node.js-based, mature ecosystem, cross-platform shell emulation
  • Bun Shell: Built into Bun, no separate install, ~10x faster, real shell semantics
  • API comparison: Both use template literals $`command`, similar ergonomics
  • Cross-platform: zx uses cross-env and handles Windows; Bun Shell has Windows support since 1.1
  • TypeScript: Both support it natively (zx via tsx; Bun natively)
  • Use zx if: Running on Node.js, need mature ecosystem, scripting CI/CD

Downloads

PackageWeekly DownloadsTrend
zx~2M↑ Growing
@google/zx~200KRebranded to zx
Bun ShellBuilt-inN/A

zx: The Node.js Shell Scripting Standard

npm install zx
# Or use without install:
npx zx script.mjs

// deploy.mjs:
#!/usr/bin/env zx

// zx globals: $, cd, echo, fetch, chalk, question, spinner
import { $ } from 'zx';

// Run commands — throws on non-zero exit by default:
await $`git pull origin main`;
await $`pnpm install --frozen-lockfile`;
await $`pnpm run build`;

// Capture output:
const branch = await $`git rev-parse --abbrev-ref HEAD`;
console.log(`Deploying branch: ${branch.stdout.trim()}`);

// Pipe commands:
const count = await $`ls -la`.pipe($`wc -l`);

// Handle errors:
try {
  await $`git tag v1.0.0`;
} catch (err) {
  console.log(`Tag failed (probably already exists): ${err.message}`);
}

// zx utility library — rich set of built-ins:
import { $, chalk, question, spinner, sleep, fetch, YAML, glob } from 'zx';

// Colorized output:
console.log(chalk.blue('Starting deployment...'));
console.log(chalk.green('✓ Build complete'));

// Interactive prompts:
const confirm = await question('Deploy to production? [y/N] ');
if (confirm !== 'y') process.exit(0);

// Spinner for long operations:
await spinner('Building...', async () => {
  await $`pnpm build`;
});

// Wait between steps:
await sleep(2000);

// HTTP requests built in:
const data = await fetch('https://api.example.com/status').then(r => r.json());

// Glob support:
const files = await glob('src/**/*.ts');

// YAML parsing:
const config = YAML.parse(await fs.readFile('config.yml', 'utf-8'));

// TypeScript with zx (requires tsx or Bun):
#!/usr/bin/env tsx

import { $ } from 'zx';

interface DeployConfig {
  env: 'staging' | 'production';
  version: string;
}

async function deploy(config: DeployConfig) {
  await $`kubectl set image deployment/app app=myapp:${config.version}`;
  await $`kubectl rollout status deployment/app`;
  console.log(`Deployed ${config.version} to ${config.env}`);
}

await deploy({ env: 'production', version: '1.2.3' });

Bun Shell: Native Performance

// Bun Shell — built into Bun, no imports needed for basic usage:
import { $ } from 'bun';

// Same template literal API as zx:
await $`git pull origin main`;
await $`bun install --frozen-lockfile`;
await $`bun run build`;

// Output capture:
const output = await $`git log --oneline -5`.text();
console.log(output);

// JSON output:
const packageJson = await $`cat package.json`.json();
console.log(packageJson.version);

// Quiet (suppress stdout/stderr):
await $`npm install`.quiet();

// Bun Shell real shell features — more powerful than zx:
import { $ } from 'bun';

// Real environment variable interpolation (shell-safe):
const name = 'my project';
await $`echo ${name}`;  // Properly quoted: "my project"

// Env vars in commands:
await $`BUILD_ENV=production bun run build`;

// Redirect to file:
await $`bun run build 2>&1`.text();

// Pipe with | operator:
const fileCount = await $`ls -la | wc -l`.text();

// Glob expansion (real shell globs):
await $`rm -f dist/*.js`;

// Async iteration over output:
for await (const line of $`tail -f logs/app.log`.lines()) {
  console.log(line);
  if (line.includes('ERROR')) break;
}

// Bun Shell error handling:
import { $ } from 'bun';

// Check exit code without throwing:
const result = await $`git tag v1.0.0`.nothrow();
if (result.exitCode !== 0) {
  console.log('Tag failed:', result.stderr.toString());
}

// Or use try/catch (throws on non-zero exit):
try {
  await $`git push --tags`;
} catch (err) {
  // err.exitCode, err.stdout, err.stderr available
  console.error('Push failed:', err.stderr.toString());
  process.exit(1);
}

Performance Comparison

Benchmark: 100 subprocess invocations (echo "hello")

zx (Node.js 24):
  Time: 8.4s
  Overhead per call: ~84ms

Bun Shell:
  Time: 0.9s
  Overhead per call: ~9ms

Speed: Bun Shell ~9x faster for subprocess invocations

Note: For I/O-bound scripts (file ops, HTTP), difference is smaller.
The gap is largest for scripts that call many subprocesses.

Feature Comparison

FeaturezxBun Shell
RuntimeNode.jsBun
Downloads2M/weekBuilt-in
TypeScriptVia tsx/BunNative
Cross-platform✅ (mature)✅ (since 1.1)
Subprocess speedGood~10x faster
chalk/colors✅ Built-inManual import
Interactive prompts✅ question()Manual
HTTP fetch()✅ Built-inNative Bun
Glob support✅ glob()Native shell
Spinner✅ spinner()Manual
YAML parsing✅ Built-inbun:yaml
Real shell pipes✅✅
Async line iterationManual✅ .lines()
JSON outputManual✅ .json()

Real-World Script Examples

// zx — CI/CD deploy script:
#!/usr/bin/env zx
import { $, chalk, spinner, echo } from 'zx';

const version = process.env.VERSION ?? (await $`git describe --tags`).stdout.trim();
echo(chalk.cyan(`Deploying ${version}...`));

await spinner('Running tests...', async () => {
  await $`pnpm test --reporter=silent`;
});

await $`docker build -t myapp:${version} .`;
await $`docker push myapp:${version}`;
await $`kubectl set image deployment/app app=myapp:${version}`;
await $`kubectl rollout status deployment/app --timeout=120s`;

echo(chalk.green(`✓ Deployed ${version} successfully`));

// Bun Shell — same script, Bun style:
#!/usr/bin/env bun
import { $ } from 'bun';

const version = process.env.VERSION 
  ?? (await $`git describe --tags`.text()).trim();
console.log(`\x1b[36mDeploying ${version}...\x1b[0m`);

await $`bun test --quiet`;
await $`docker build -t myapp:${version} .`;
await $`docker push myapp:${version}`;
await $`kubectl set image deployment/app app=myapp:${version}`;
await $`kubectl rollout status deployment/app --timeout=120s`;

console.log(`\x1b[32m✓ Deployed ${version} successfully\x1b[0m`);

Decision Guide

Choose zx if:
  → Running on Node.js (not Bun)
  → Need spinner, chalk, question() built-in
  → CI/CD on GitHub Actions (Node.js default)
  → Team not using Bun yet
  → Want mature, widely-used tooling

Choose Bun Shell if:
  → Already using Bun in your project
  → Performance matters (many subprocess calls)
  → Native TypeScript without tsx
  → Want real shell semantics (proper quoting, globs)
  → Building Bun-native tooling or CLI

Use neither (plain child_process) if:
  → Need fine-grained process control
  → Long-running processes with complex IPC
  → Embedding in a Node.js library (no external deps)

Compare zx and Bun download trends on PkgPulse.

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