detect-unused-deps

Find unused, missing, and phantom dependencies in your Node.js projects. Zero dependencies. Works with monorepos.

Install

# Run directly (no install needed)
npx detect-unused-deps

# Or install globally
npm i -g detect-unused-deps

Usage

# Scan current directory
detect-unused-deps

# Scan a specific directory
detect-unused-deps ./packages/my-app

# JSON output (great for CI)
detect-unused-deps --json

# Ignore specific packages (plugins, implicit deps)
detect-unused-deps --ignore @types/node,webpack-cli,babel-plugin-transform-runtime

What it detects

| Category | Description | |---|---| | Unused dependencies | Listed in dependencies but never imported | | Unused devDependencies | Listed in devDependencies but never imported | | Missing dependencies | Imported in code but not in package.json |

Features

• 🔍 Scans .js, .jsx, .ts, .tsx, .mjs, .cjs, .mts, .cts files
• 📦 Handles import, require(), dynamic import(), and re-exports
• 🏗️ Supports scoped packages (@scope/pkg)
• 🎯 Ignores node_modules, dist, build, .git, etc.
• 🌈 Color-coded terminal output
• 📊 JSON output for CI/CD pipelines
• 🚫 Zero dependencies
• ⚡ Fast — pure filesystem scan, no AST parsing overhead

Programmatic API

const { analyze } = require('detect-unused-deps');

const result = analyze('./my-project', {
  ignore: ['@types/node']
});

console.log(result);
// {
//   unused: ['lodash'],
//   unusedDev: ['jest'],
//   missing: ['chalk'],
//   stats: { filesScanned: 42, totalDeps: 10, totalDevDeps: 5, uniqueImports: 15 }
// }

Exit codes

| Code | Meaning | |---|---| | 0 | No issues found | | 1 | Unused or missing dependencies detected | | 2 | Error (e.g., no package.json) |

Tips

Some packages are used implicitly (Babel plugins, ESLint configs, type definitions). Use --ignore to skip them:

detect-unused-deps --ignore @types/node,eslint-config-prettier,babel-plugin-transform-runtime

License

MIT