Web quality audit
/SKILLComprehensive web quality audit covering performance, accessibility, SEO, and best practices.
--- name: web-quality-audit description: Comprehensive web quality audit covering performance, accessibility, SEO, and best practices. Use when asked to "audit my site", "review web quality", "run lighthouse audit", "check page quality", or "optimize my website". license: MIT metadata: author: web-quality-skills version: "1.0" --- # Web quality audit Comprehensive quality review based on Google Lighthouse audits. Covers Performance, Accessibility, SEO, and Best Practices across 150+ checks. > Lighthouse v13 note (Oct 2025+). Lighthouse has migrated the Performance category from per-opportunity audits to Performance Insight Audits ([announcement](https://developer.chrome.com/blog/moving-lighthouse-to-insights)). Several individual audit names this skills historically referenced : First Meaningful Paint, No Document Write, Uses Passive Event Listeners, Uses Rel Preload : have been removed or merged. The underlying advice is unchanged and still applies; only the report format moved. The CLS-related audits ("layout shifts", "non-composited animations", "unsized images") are now consolidated into a single cls-culprits-insight, and image audits are merged into image-delivery-insight. Treat older Lighthouse JSON output as a superset, not a contradiction. ## How it works 1. Analyze the provided code/project for quality issues 2. Categorize findings by severity (Critical, High, Medium, Low) 3. Provide specific, actionable recommendations 4. Include code examples for fixes ## Audit categories ### Performance (40% of typical issues) Core Web Vitals : Must pass for good page experience: LCP (Largest Contentful Paint) < 2.5s. The largest visible element must render quickly. Optimize images, fonts, and server response time. INP (Interaction to Next Paint) < 200ms. User interactions must feel instant. Reduce JavaScript execution time and break up long tasks. CLS (Cumulative Layout Shift) < 0.1. Content must not jump around. Set explicit dimensions on images, embeds, and ads. Resource Optimization: Compress images. Use WebP/AVIF with fallbacks. Serve correctly sized images via srcset. Minimize JavaScript. Remove unused code. Use code splitting. Defer non-critical scripts. Optimize CSS. Extract critical CSS. Remove unused styles. Avoid @import. Efficient fonts.* Use font-display: swap. Preload critical fonts. Subset to needed characters. Loading Strategy: Preconnect to origins.* Add <link rel="preconnect"> for third-party domains. Preload critical assets. LCP images, fonts, and above-fold CSS. Lazy load below-fold content. Images, iframes, and heavy components. Cache effectively. Long cache TTLs for static assets. Immutable caching for hashed files. ### Accessibility (30% of typical issues) Perceivable: Text alternatives. Every <img> has meaningful alt text. Decorative images use alt="". Color contrast. Minimum 4.5:1 for normal text, 3:1 for large text (WCAG AA). Don't rely on color alone. Use icons, patterns, or text alongside color indicators. Captions and transcripts. Video has captions. Audio has transcripts. Operable: Keyboard accessible. All functionality available via keyboard. No keyboard traps. Focus visible. Clear focus indicators on all interactive elements. Skip links. Provide "Skip to main content" for keyboard users. Sufficient time. Users can extend time limits. No auto-advancing content without controls. Understandable: Page language. Set lang attribute on <html>. Consistent navigation. Same navigation structure across pages. Error identification. Form errors clearly described and associated with fields. Labels and instructions. All form inputs have associated labels. Robust: Valid HTML. No duplicate IDs. Properly nested elements. ARIA used correctly. Prefer native elements. ARIA roles match behavior. Name, role, value. Interactive elements have accessible names and correct roles. ### SEO (15% of typical issues) Crawlability: Valid robots.txt. Doesn't block important resources. XML sitemap. Lists all important pages. Submitted to Search Console. Canonical URLs. Prevent duplicate content issues. No noindex on important pages. Check meta robots and headers. On-Page SEO: Unique title tags. 50-60 characters. Primary keyword included. Meta descriptions. 150-160 characters. Compelling and unique. Heading hierarchy.* Single <h1>. Logical heading structure. Descriptive link text. Not "click here" or "read more". Technical SEO: Mobile-friendly. Responsive design. Tap targets ≥ 48px. HTTPS. Secure connection required. Fast loading. Performance directly impacts ranking. Structured data. JSON-LD for rich snippets (Article, Product, FAQ, etc.). ### Best practices (15% of typical issues) *Securit
