Google Lighthouse

# Basic audit (generates HTML report)
lighthouse https://example.com

# Desktop preset (default is mobile)
lighthouse https://example.com --preset=desktop

# Generate JSON report to a file
lighthouse https://example.com --output=json --output-path=./report

# Run only specific categories
lighthouse https://example.com --only-categories=performance,accessibility

# Enforce a performance budget
lighthouse https://example.com --budget-path=./budget.json

import lighthouse from 'lighthouse';
import * as chromeLauncher from 'chrome-launcher';

// Launch a headless Chrome instance
const chrome = await chromeLauncher.launch({
  chromeFlags: ['--headless']
});

// Run Lighthouse audit
const result = await lighthouse('https://example.com', {
  logLevel: 'info',
  output: 'json',
  onlyCategories: ['performance'],
  port: chrome.port,
});

// Access results
const perfScore = result.lhr.categories.performance.score * 100;
console.log(`Performance: ${perfScore}/100`);

// Save report
const reportHtml = result.report;
fs.writeFileSync('report.html', reportHtml);

// Clean up
await chrome.kill();

# .github/workflows/lighthouse-ci.yml
name: Lighthouse CI
on: [push, pull_request]

jobs:
  lighthouse:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: 22

      - name: Build application
        run: npm ci && npm run build

      - name: Run Lighthouse CI
        uses: treosh/lighthouse-ci-action@v12
        with:
          runs: 3                    # Average 3 runs
          configPath: './lighthouserc.json'
          uploadArtifacts: true

      - name: Assert thresholds
        run: npx @lhci/cli assert    # Fail if below budget