Monthly Performance Audit Checklist

Performance isn't a one-time fix — it's an ongoing practice. Use this monthly checklist to catch regressions before they impact users and revenue.

Weekly Quick Check (5 Minutes)

• Check automated monitoring dashboard for score drops
• Review any performance alert emails
• Spot-check top 3 landing pages in Lighthouse

Monthly Deep Audit (60-90 Minutes)

1. Core Web Vitals Review

Run Lighthouse on your top 5 pages (mobile):

• Homepage
• Most popular landing page
• Product/pricing page
• Blog index
• Conversion page (signup/checkout)

Record scores in a spreadsheet:

Page	LCP	INP	CLS	Score	Last Month
Homepage
Landing
Pricing
Blog
Signup

2. Third-Party Script Audit

• List all third-party scripts loading on your site
• Check if any new scripts were added (marketing team often adds without telling engineering)
• Verify each script is still needed and actively used
• Check for duplicate analytics (common: GA4 + GTM GA4 = double counting)
• Test removing any script that hasn't been reviewed in 3 months

3. Image Audit

• Check for any new unoptimized images uploaded
• Verify new images use WebP/AVIF format
• Check for oversized images (3000px wide for a 300px thumbnail)
• Verify lazy loading on below-fold images
• Check that hero/LCP images are NOT lazy loaded

4. JavaScript Bundle Check

• Check total JS bundle size (should be under 200KB compressed)
• Review any new dependencies added to package.json
• Check for unused dependencies
• Verify code splitting is working (check network tab)

5. CSS Review

• Check total CSS size (should be under 100KB compressed)
• Look for unused CSS (Coverage tab in DevTools)
• Verify critical CSS is inlined or preloaded
• Check for render-blocking stylesheets

6. Caching Verification

• Check Cache-Control headers on static assets
• Verify CDN cache hit rate (should be >90%)
• Test a repeat visit — are assets served from cache?
• Check service worker (if applicable) isn't caching stale content

7. Font Check

• Verify font-display: swap on all custom fonts
• Check that fonts are preloaded
• Confirm no more than 2-3 font families, 3-4 weights
• Check for FOIT (Flash of Invisible Text) on slow connections

8. Layout Stability

• Check CLS on all key pages
• Verify all images have width/height attributes
• Check for late-loading ads or banners causing shifts
• Test dynamic content injection (cookie banners, chat widgets)

Quarterly Deep Dive (4 Hours)

Infrastructure Review

• Review hosting performance (TTFB trends)
• Check CDN configuration and edge caching
• Review database query performance (if applicable)
• Test from multiple geographic locations

Competitive Analysis

• Run Lighthouse on top 3 competitors
• Compare Core Web Vitals using CrUX data
• Identify areas where competitors are faster
• Set targets to match or beat their scores

Performance Budget Review

• Review performance budget targets
• Check if any budgets have been exceeded
• Adjust budgets based on new features/requirements
• Present performance report to stakeholders

Automation Recommendations

Automate What You Can

• Monitoring: Use BadPageSpeed for automated scheduled scans
• Build checks: Add Lighthouse CI to your deployment pipeline
• Image optimization: Use a build-time image optimization plugin
• Bundle analysis: Run bundle analyzer monthly
• Alerts: Set up email alerts for score drops

Track What You Can't Automate

• Third-party script decisions
• Performance budget negotiations
• Architecture decisions
• Vendor evaluations

Start Your Performance Routine

BadPageSpeed automates the monitoring piece so you can focus on the analysis and action items.

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