Lighthouse Audit
Automate Google Lighthouse audits to measure and track Core Web Vitals, SEO, and accessibility - the same metrics Google uses for search ranking.
When to Use This Skill
- •Performance optimization - Measure LCP, FID, CLS before and after changes
- •SEO audits - Check technical SEO issues (meta tags, structured data, etc.)
- •Accessibility checks - Identify a11y issues for compliance
- •Client reporting - Generate professional performance reports
- •Monitoring - Track scores over time across multiple pages
What Claude Does vs What You Decide
| Claude Does | You Decide |
|---|---|
| Structures analysis frameworks | Metric definitions |
| Identifies patterns in data | Business interpretation |
| Creates visualization templates | Dashboard design |
| Suggests optimization areas | Action priorities |
| Calculates statistical measures | Decision thresholds |
Dependencies
bash
pip install click pandas jinja2 # Also requires Chrome and Lighthouse CLI # npm install -g lighthouse # Or use Chrome DevTools built-in Lighthouse
Commands
Single URL Audit
bash
python scripts/main.py audit https://example.com --categories performance,seo python scripts/main.py audit https://example.com --format html --output report.html
Batch Audit
bash
python scripts/main.py batch urls.txt --output results/ python scripts/main.py batch urls.txt --categories performance --format csv
Compare Before/After
bash
python scripts/main.py compare https://example.com --baseline scores.json python scripts/main.py compare https://example.com --baseline-url https://staging.example.com
Monitor Over Time
bash
python scripts/main.py history https://example.com --days 30 python scripts/main.py history https://example.com --plot
Examples
Example 1: Full Site Performance Audit
bash
# Create URL list cat > urls.txt << EOF https://example.com/ https://example.com/pricing https://example.com/features https://example.com/blog EOF # Run batch audit python scripts/main.py batch urls.txt --categories performance,seo,accessibility # Output: results/audit_2024-01-15/ # ├── example.com_.json # ├── example.com_pricing.json # ├── example.com_features.json # ├── example.com_blog.json # └── summary.csv
Example 2: Before/After Comparison
bash
# Save baseline python scripts/main.py audit https://example.com --output baseline.json # Make optimizations... # Compare python scripts/main.py compare https://example.com --baseline baseline.json # Output: # Core Web Vitals Comparison # ───────────────────────────── # Metric Before After Change # LCP 3.2s 1.8s -44% ✓ # FID 120ms 45ms -63% ✓ # CLS 0.25 0.08 -68% ✓ # Performance 52 89 +37 pts
Example 3: Generate Client Report
bash
# Full audit with HTML report python scripts/main.py audit https://client-site.com \ --format html \ --output client-report.html \ --include-screenshots # Output: Professional HTML report with: # - Executive summary # - Core Web Vitals scores # - Screenshots of issues # - Prioritized recommendations
Audit Categories
| Category | Checks | Impact |
|---|---|---|
performance | LCP, FID, CLS, TTFB, Speed Index | Search ranking |
seo | Meta tags, headings, links, mobile | Search visibility |
accessibility | WCAG compliance, contrast, labels | Compliance |
best-practices | HTTPS, security, modern APIs | Trust |
pwa | Service worker, manifest, offline | App-like experience |
Core Web Vitals Thresholds
| Metric | Good | Needs Improvement | Poor |
|---|---|---|---|
| LCP (Largest Contentful Paint) | ≤2.5s | 2.5s-4.0s | >4.0s |
| FID (First Input Delay) | ≤100ms | 100ms-300ms | >300ms |
| CLS (Cumulative Layout Shift) | ≤0.1 | 0.1-0.25 | >0.25 |
| INP (Interaction to Next Paint) | ≤200ms | 200ms-500ms | >500ms |
Output Formats
| Format | Use Case | Content |
|---|---|---|
json | Automation, storage | Full raw data |
csv | Spreadsheets, analysis | Summary scores |
html | Client reports | Visual report |
md | Documentation | Markdown summary |
Skill Boundaries
What This Skill Does Well
- •Structuring data analysis
- •Identifying patterns and trends
- •Creating visualization frameworks
- •Calculating statistical measures
What This Skill Cannot Do
- •Access your actual data
- •Replace statistical expertise
- •Make business decisions
- •Guarantee prediction accuracy
Related Skills
- •schema-markup - Fix structured data issues
- •image-batch - Optimize images for LCP
- •link-checker - Find broken links
Skill Metadata
- •Mode: centaur
yaml
category: seo-tools subcategory: performance dependencies: [lighthouse, click, pandas] difficulty: beginner time_saved: 3+ hours/week