Benchmark

The benchmark feature allows you to compare the performance of different compressors. It measures compression ratio, speed, and output size to help you choose the best compressor for your needs.

Installation

npm install @node-minify/benchmark

Or use it via the CLI (included with @node-minify/cli):

npm install -g @node-minify/cli

CLI Usage

Basic Usage

node-minify benchmark src/app.js

Compare Specific Compressors

node-minify benchmark src/app.js --compressors terser,esbuild,swc

Custom Compressors

You can benchmark custom compressors (npm packages or local files):

# Mix built-in and custom compressors
node-minify benchmark src/app.js --compressors terser,./my-compressor.js,my-custom-package

See the Custom Compressors documentation for details.

With Options

# Run 3 iterations for more accurate timing
node-minify benchmark src/app.js -c terser,esbuild -n 3

# Include gzip size in results
node-minify benchmark src/app.js -c terser,esbuild --gzip

# Specify file type (required for esbuild, lightningcss)
node-minify benchmark src/app.js -c terser,esbuild -t js

Output Formats

# Console output (default) - colored table
node-minify benchmark src/app.js -f console

# JSON output - machine readable
node-minify benchmark src/app.js -f json

# Markdown output - for documentation
node-minify benchmark src/app.js -f markdown

Save to File

node-minify benchmark src/app.js -f json -o results.json
node-minify benchmark src/app.js -f markdown -o BENCHMARK.md

Programmatic API

Basic Usage

import { benchmark } from '@node-minify/benchmark';

const results = await benchmark({
  input: 'src/app.js',
  compressors: ['terser', 'esbuild', 'swc']
});

console.log(results.summary.recommended);

With Options

import { benchmark, getReporter } from '@node-minify/benchmark';

const results = await benchmark({
  input: 'src/**/*.js',
  compressors: ['terser', 'esbuild', 'swc', 'uglify-js'],
  iterations: 3,        // Run each compressor 3 times
  warmup: 1,            // Warmup run before timing
  includeGzip: true,    // Include gzip size
  type: 'js'            // File type
});

// Use a reporter to format output
const consoleOutput = getReporter('console')(results);
console.log(consoleOutput);

// Or access results directly
for (const file of results.files) {
  console.log(`File: ${file.file} (${file.originalSize})`);
  for (const result of file.results) {
    if (result.success) {
      console.log(`  ${result.compressor}: ${result.size} (${result.reductionPercent}%)`);
    }
  }
}

Options Reference

Result Structure

interface BenchmarkResult {
  timestamp: string;
  options: BenchmarkOptions;
  files: FileResult[];
  summary: {
    bestCompression: string;  // Smallest output
    bestPerformance: string;  // Fastest
    recommended: string;      // Best balance
  };
}

interface FileResult {
  file: string;
  originalSizeBytes: number;
  originalSize: string;
  results: CompressorMetrics[];
}

interface CompressorMetrics {
  compressor: string;
  sizeBytes: number;
  size: string;
  timeMs: number;
  reductionPercent: number;
  gzipSize?: string;
  brotliSize?: string;
  iterationTimes?: number[];
  success: boolean;
  error?: string;
}

Example Output

Console Format

🔍 Benchmarking: src/app.js (45.2 KB)
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

Compressor      Size      Reduction   Time      Status
──────────────────────────────────────────────────────
esbuild         12.3 KB   72.8%       45ms      OK
terser          11.8 KB   73.9%       234ms     OK
swc             12.1 KB   73.2%       67ms      OK
uglify-js       11.9 KB   73.7%       456ms     OK

━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

🏆 Best compression: terser
⚡ Fastest: esbuild
💡 Recommended: esbuild

JSON Format

{
  "timestamp": "2026-01-02T10:30:00Z",
  "options": {
    "input": "src/app.js",
    "compressors": ["terser", "esbuild"]
  },
  "files": [{
    "file": "src/app.js",
    "originalSizeBytes": 46284,
    "originalSize": "45.2 KB",
    "results": [
      {
        "compressor": "terser",
        "sizeBytes": 12083,
        "size": "11.8 KB",
        "timeMs": 234,
        "reductionPercent": 73.9,
        "success": true
      },
      {
        "compressor": "esbuild",
        "sizeBytes": 12595,
        "size": "12.3 KB",
        "timeMs": 45,
        "reductionPercent": 72.8,
        "success": true
      }
    ]
  }],
  "summary": {
    "bestCompression": "terser",
    "bestPerformance": "esbuild",
    "recommended": "esbuild"
  }
}

Markdown Format

# Benchmark Results

**File:** src/app.js (45.2 KB)
**Date:** 2026-01-02T10:30:00Z

| Compressor | Size | Reduction | Time |
|------------|------|-----------|------|
| terser     | 11.8 KB | 73.9% | 234ms |
| esbuild    | 12.3 KB | 72.8% | 45ms |

## Summary

- 🏆 **Best compression:** terser
- ⚡ **Fastest:** esbuild
- 💡 **Recommended:** esbuild

Supported Compressors

JavaScript

• terser - Recommended, modern and well-maintained
• esbuild - Extremely fast, also handles CSS
• swc - Rust-based, very fast
• oxc - Rust-based, cutting-edge
• uglify-js - Classic, battle-tested
• google-closure-compiler - Advanced optimizations

CSS

• lightningcss - Rust-based, fastest
• esbuild - Also handles JS
• clean-css - Feature-rich
• cssnano - PostCSS-based
• csso - Structural optimizations

HTML

• html-minifier - Feature-rich HTML minifier
• minify-html - Rust-based, high performance

Tips

1. Use multiple iterations for more accurate timing results
2. Warmup runs help avoid JIT compilation overhead
3. Include gzip size for realistic production comparisons
4. Specify file type when using compressors like esbuild that require it