WordPress Site Speed Auditor

This skill provides a comprehensive performance audit framework for WordPress sites, themes, and plugins.

When to Use This Skill

Invoke this skill when:

• Analyzing a WordPress theme or plugin for performance issues
• User requests a site speed audit or performance review
• Investigating slow page loads or performance complaints
• Optimizing a WordPress site for better Core Web Vitals
• Reviewing code before deployment to catch performance issues

Audit Checklist

1. Image & Media Optimization

Check for:

• Image formats - Are modern formats (WebP, AVIF) used? Check for JPEG/PNG that could be converted
• Image compression - Are images optimized/compressed? Look for large file sizes (>100KB for thumbnails, >500KB for full-size)
• Lazy loading - Is loading="lazy" attribute present on images below the fold?
• Responsive images - Are srcset and sizes attributes used for different screen sizes?
• Image dimensions - Are images sized correctly in code or oversized and scaled down with CSS?
• Video hosting - Are videos self-hosted (bad) or externally hosted on YouTube/Vimeo (good)?
• Video lazy loading - Do videos use lazy loading or load on user interaction?
• Background images - Are large background images optimized and served responsively?
• Favicon size - Is favicon appropriately sized (not a 500KB PNG)?
• SVG optimization - Are SVG files minified and cleaned of unnecessary metadata?

Recommendations:

• Convert JPEG/PNG to WebP (30% smaller file sizes)
• Use lazy loading for all images below the fold
• Implement responsive images with srcset
• Use external video hosting (YouTube, Vimeo) with lazy loading
• Optimize images before upload or use plugins (Smush, ShortPixel, Imagify)

2. Database & Query Optimization

Check for:

• N+1 queries - Multiple queries in loops (check WP_Query inside loops)
• Unoptimized queries - Complex queries without proper indexing
• Post revisions - Excessive post revisions in database
• Transients - Expired transients not cleaned up
• Autoloaded data - Excessive autoloaded options (>1MB is concerning)
• Database size - Bloated database with spam comments, trashed posts
• Query caching - Missing object caching for repeated queries
• Direct SQL - Raw $wpdb queries that bypass caching
• Meta queries - Inefficient meta_query usage without indexes
• Taxonomies - Heavy taxonomy queries without caching

Tools to use:

• Query Monitor plugin - Identifies slow queries and query counts
• WP-CLI: wp db optimize - Optimize database tables
• WP-CLI: wp transient delete --all - Clear expired transients
• WP-CLI: wp post list --post_type=revision --format=count - Count revisions

Recommendations:

• Limit post revisions in wp-config.php: define('WP_POST_REVISIONS', 3);
• Clean database regularly (WP-Optimize plugin)
• Implement object caching (Redis, Memcached)
• Add indexes for frequently queried meta keys
• Use transients for expensive query results
• Implement proper query result caching

3. Plugin & Theme Performance

Check for:

• Plugin count - More than 20-25 active plugins is concerning
• Heavy plugins - Plugins loading excessive resources (use Query Monitor)
• Outdated plugins - Old plugins not updated for modern PHP/WordPress
• Plugin conflicts - Multiple plugins doing similar things
• Unused features - Theme or plugin features loaded but not used
• Bloated themes - Themes with excessive built-in features
• Page builders - Heavy page builders (Elementor, Divi) when not needed
• Third-party scripts - Excessive external scripts (analytics, ads, social)
• Font loading - Multiple font weights/variants loaded unnecessarily
• Icon libraries - Full Font Awesome loaded for 2-3 icons

Recommendations:

• Deactivate and remove unused plugins
• Replace heavy plugins with lightweight alternatives
• Use Query Monitor to identify resource-intensive plugins
• Choose lightweight themes (GeneratePress, Astra, Kadence)
• Avoid page builders for simple sites
• Limit font weights and character sets
• Use SVG icons instead of icon fonts

4. Caching Implementation

Check for:

• Page caching - Is static HTML being generated and served?
• Browser caching - Are proper cache headers set for static assets?
• Object caching - Is persistent object caching (Redis/Memcached) enabled?
• Opcode caching - Is OPcache enabled on the server?
• Cache preloading - Is cache automatically generated for critical pages?
• Cache exclusions - Are dynamic pages (cart, checkout) properly excluded?
• CDN integration - Are static assets served from a CDN?
• Cache invalidation - Does cache clear properly on content updates?

Recommendations:

• Install caching plugin (WP Rocket, WP Super Cache, W3 Total Cache)
• Enable page caching for anonymous users
• Implement object caching with Redis or Memcached
• Configure browser caching with far-future expiration headers
• Use CDN (Cloudflare, BunnyCDN, StackPath) for static assets
• Enable cache preloading for better first-visit performance

5. Asset Optimization (CSS/JS)

Check for:

• Render-blocking resources - CSS/JS blocking initial page render
• Unminified assets - CSS/JS files not minified
• Uncombined files - Multiple small CSS/JS files not combined
• Unused CSS - Large CSS files with unused selectors
• Unused JavaScript - Heavy JS libraries loaded but barely used
• Inline critical CSS - Critical above-the-fold CSS not inlined
• Deferred JavaScript - Non-critical JS not deferred or async
• jQuery dependency - Unnecessary jQuery for simple interactions
• Legacy JavaScript - Old JS not using modern ES6+ features
• Source maps - Source maps loaded in production

Recommendations:

• Minify CSS/JS files (Autoptimize, WP Rocket)
• Combine files where appropriate (be careful with HTTP/2)
• Defer non-critical JavaScript with defer or async attributes
• Inline critical above-the-fold CSS
• Remove unused CSS (PurgeCSS, UnCSS)
• Load JavaScript in footer when possible
• Use vanilla JavaScript instead of jQuery for simple tasks
• Enable GZIP/Brotli compression (reduces files by 70-90%)

6. Server & Hosting Configuration

Check for:

• PHP version - Using PHP 7.4 or older (should be 8.1+)
• Server resources - Memory limits, max execution time
• HTTP/2 or HTTP/3 - Modern HTTP protocol support
• GZIP/Brotli compression - Compression enabled for text assets
• Keep-Alive - Connection persistence enabled
• DNS lookup time - Slow DNS resolution
• Server location - Geographic distance from target audience
• Shared hosting - Resource limitations from shared environment
• Server response time - TTFB (Time To First Byte) over 200ms

Recommendations:

• Upgrade to PHP 8.1 or 8.2 (30-50% performance improvement)
• Increase PHP memory limit to at least 256MB
• Ensure HTTP/2 or HTTP/3 is enabled
• Enable GZIP or Brotli compression
• Use quality managed WordPress hosting (WP Engine, Kinsta, Cloudways)
• Consider upgrading from shared to VPS/dedicated hosting
• Use server closer to target audience or implement CDN

7. Core Web Vitals & User Experience

Check for:

• Largest Contentful Paint (LCP) - Should be under 2.5 seconds
• First Input Delay (FID) - Should be under 100 milliseconds
• Cumulative Layout Shift (CLS) - Should be under 0.1
• First Contentful Paint (FCP) - Should be under 1.8 seconds
• Time to Interactive (TTI) - Should be under 3.8 seconds
• Total Blocking Time (TBT) - Should be under 200 milliseconds
• Layout shifts - Images without dimensions causing shifts
• Font loading - FOUT (Flash of Unstyled Text) or FOIT (Flash of Invisible Text)

Tools to measure:

• Google PageSpeed Insights
• GTmetrix
• WebPageTest
• Chrome DevTools Lighthouse
• Core Web Vitals Chrome extension

Recommendations:

• Optimize LCP element (usually hero image or heading)
• Add width/height attributes to images to prevent CLS
• Use font-display: swap for web fonts
• Minimize JavaScript execution time for better FID/TBT
• Implement critical CSS for faster FCP
• Preload key resources (fonts, hero images)

8. HTTP Requests & Resource Loading

Check for:

• Total HTTP requests - More than 50 requests is concerning
• Third-party requests - Excessive external domain requests
• Duplicate resources - Same resource loaded multiple times
• Large resources - Files over 1MB being loaded
• Blocking resources - Resources blocking page render
• Preconnect/prefetch - Missing resource hints for external domains
• Lazy loading scripts - Scripts loading when not needed
• Analytics overhead - Multiple tracking scripts

Recommendations:

• Reduce total HTTP requests (combine files, use sprites)
• Minimize third-party script usage
• Use resource hints: preconnect, dns-prefetch, preload
• Defer non-critical resources
• Implement lazy loading for images and iframes
• Consolidate analytics tools (use Google Tag Manager)
• Remove duplicate resources

9. WordPress-Specific Optimizations

Check for:

• Heartbeat API - Running too frequently
• Embeds - wp-embed.js loading when not needed
• Emojis - Emoji script/styles loading unnecessarily
• Dashicons - Dashicons loading on frontend
• REST API - Excessive REST API calls on frontend
• wp-cron - Heavy scheduled tasks during peak traffic
• Gutenberg styles - Block styles loading when not using blocks
• jQuery Migrate - Old jQuery migrate script still loading

Recommendations:

• Disable/limit Heartbeat API frequency
• Remove emoji scripts if not needed
• Dequeue Dashicons on frontend (unless using them)
• Disable embeds if not using WordPress embeds
• Replace wp-cron with real cron jobs
• Remove jQuery Migrate if not needed
• Conditionally load Gutenberg styles only when needed

10. Code Quality & Best Practices

Check for:

• Inline styles - Excessive inline CSS in HTML
• Inline scripts - JavaScript directly in HTML
• External dependencies - Heavy external libraries for simple tasks
• Unoptimized loops - Expensive operations in loops
• File I/O in loops - File reads/writes in repeated operations
• Remote requests - API calls without caching/timeouts
• Error suppression - Using @ operator hiding performance issues
• Debug mode - WP_DEBUG enabled in production
• Disabled caching - Development constants in production

Recommendations:

• Move inline styles to external stylesheets
• Move inline scripts to external files
• Cache expensive operation results
• Avoid file operations in loops
• Cache external API responses with transients
• Remove debug mode and development constants in production
• Use WordPress coding standards and best practices

Audit Output Format

Provide audit results in this structure:

## WordPress Performance Audit Results

### Critical Issues (Fix Immediately)
1. [Issue] - [Impact] - [Recommendation]

### High Priority (Fix Soon)
1. [Issue] - [Impact] - [Recommendation]

### Medium Priority (Optimize When Possible)
1. [Issue] - [Impact] - [Recommendation]

### Low Priority (Nice to Have)
1. [Issue] - [Impact] - [Recommendation]

### Strengths (Already Optimized)
1. [What's working well]

## Estimated Performance Impact
- Current estimated load time: [X] seconds
- After optimizations: [Y] seconds
- Potential improvement: [Z]%

## Implementation Priority
1. [First thing to fix - highest impact/effort ratio]
2. [Second priority]
3. [Third priority]

Key Performance Metrics to Report

Always include these metrics when available:

• Page load time (target: <3 seconds)
• Time to First Byte (target: <200ms)
• Total page size (target: <2MB)
• Number of HTTP requests (target: <50)
• Largest Contentful Paint (target: <2.5s)
• First Input Delay (target: <100ms)
• Cumulative Layout Shift (target: <0.1)

Tools & Commands Reference

WP-CLI Commands:

wp plugin list --status=active  # List active plugins
wp db optimize                  # Optimize database
wp transient delete --all       # Clear transients
wp cache flush                  # Clear cache
wp option list --autoload=yes   # Check autoloaded options

Query Monitor Checks:

• Database queries (count and slow queries)
• HTTP API requests
• Hooks & actions
• Scripts & styles
• Languages (translation files)

Browser DevTools:

• Network tab - Resource sizes and timing
• Performance tab - Flame charts and bottlenecks
• Lighthouse - Core Web Vitals and performance score
• Coverage tab - Unused CSS/JS

Remember

• Focus on high-impact, low-effort optimizations first
• Measure before and after every optimization
• Test on real devices with throttled connections
• Don't over-optimize - diminishing returns after core issues fixed
• Mobile performance is critical for SEO and user experience
• Core Web Vitals directly impact Google rankings