lighthouse

name	lighthouse
description	Web performance audit with Google Lighthouse
metadata	{"openclaw":{"always":false,"emoji":"🏠"}}

Lighthouse

Audit performance, accessibility, SEO and best practices for websites.

Setup

1. Check if installed:

   command -v node && node --version
   command -v npx && npx lighthouse --version 2>/dev/null || npm list -g lighthouse 2>/dev/null
   

2. Install:

   # Node.js (required for npx / lighthouse)
   # macOS
   brew install node
   
   # Ubuntu / Debian
   sudo apt update && sudo apt install -y nodejs npm
   
   # Lighthouse (use npx, no install needed)
   npx lighthouse <url> --output=json --chrome-flags="--headless --no-sandbox"
   
   # Or install globally
   npm install -g lighthouse
   

Run Audit

# Full audit (output to terminal)
npx lighthouse <url> --output=json --chrome-flags="--headless --no-sandbox" 2>/dev/null | jq '{
  performance: .categories.performance.score,
  accessibility: .categories.accessibility.score,
  bestPractices: .categories["best-practices"].score,
  seo: .categories.seo.score
}'

# Save HTML report
npx lighthouse <url> --output=html --output-path=./lighthouse-report.html --chrome-flags="--headless --no-sandbox"

# Performance only
npx lighthouse <url> --only-categories=performance --output=json --chrome-flags="--headless --no-sandbox"

Categories

Category	What it measures
Performance	LCP, FID, CLS, TTFB, speed index
Accessibility	Contrast, alt text, ARIA, keyboard navigation
Best Practices	HTTPS, console errors, deprecated APIs
SEO	Meta tags, structured data, mobile-friendly

Interpret Scores

• 90-100: Good (green)
• 50-89: Needs Improvement (orange)
• 0-49: Poor (red)

Key Metrics (Core Web Vitals)

Metric	Good	Needs Improvement	Poor
LCP (Largest Contentful Paint)	< 2.5s	2.5s - 4s	> 4s
FID (First Input Delay)	< 100ms	100ms - 300ms	> 300ms
CLS (Cumulative Layout Shift)	< 0.1	0.1 - 0.25	> 0.25

Compare Results

# Run multiple times and compare
for i in 1 2 3; do
  npx lighthouse <url> --output=json --chrome-flags="--headless --no-sandbox" 2>/dev/null | \
    jq -r '"Run '$i': perf=\(.categories.performance.score) a11y=\(.categories.accessibility.score)"'
done

Tips

• Run 3+ times and average (results vary)
• Use --chrome-flags="--headless --no-sandbox" for servers
• Scores are multiplied by 100 (0.95 = 95 points)
• Use --preset=desktop to simulate desktop (default is mobile)
• Install Chrome/Chromium on server if not available