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Web Quality Audit

Free

Perform a comprehensive web quality review in one go.

by tech-leads-club5k stars on tech-leads-club/agent-skills
Updated Aug 5, 2026
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Free · Opens the source repo

What Web Quality Audit does

The Web Quality Audit skill provides a thorough evaluation of your website's performance, accessibility, SEO, and adherence to best practices. By leveraging Google Lighthouse audits, it conducts over 150 checks to identify areas of improvement across multiple domains. This skill is particularly useful for developers and designers who need a holistic view of their site's quality without running separate audits for each category.

When you initiate an audit, the skill analyzes the provided code or project, categorizing findings by severity—Critical, High, Medium, and Low. It offers actionable recommendations along with code examples for each identified issue, ensuring that users receive clear guidance on how to resolve problems. This structured approach allows teams to prioritize fixes based on the severity of the issues, making it easier to enhance site quality systematically.

The skill is designed for those who want to ensure their websites meet modern standards and provide a good user experience. It is particularly beneficial for teams preparing for a launch or those looking to improve existing sites. However, it is important to note that this skill is not intended for single-area audits. For focused assessments, users should consider specialized tools for core web vitals, accessibility, SEO, or best practices.

Overall, the Web Quality Audit skill is an essential tool for developers and designers aiming to optimize their websites comprehensively, ensuring that they meet performance benchmarks, accessibility standards, and SEO best practices.

When to use it

Use this skill when you need a complete overview of your website's quality across performance, accessibility, SEO, and best practices in a single review.

When not to use it

Avoid using this skill for audits focused on a single area; instead, opt for specialized tools for more in-depth analysis in those categories.

What you can build with it

Pre-Launch Website Review

Before launching a new website, use this skill to ensure all quality aspects are covered and optimized.

Regular Site Maintenance

Schedule audits regularly to maintain high performance and compliance with accessibility and SEO standards.

Client Project Evaluation

Utilize this skill to provide clients with a comprehensive report on their website's quality and areas for improvement.

How to install Web Quality Audit

View source

1. Install with the skills CLI

npx skills add tech-leads-club/agent-skills/web-quality-audit --agent claude-code

2. Or install it manually

Download the skill folder and drop it into ~/.claude/skills/ for all projects, or .claude/skills/ to scope it to one repo. Restart Claude Code so it picks up the new skill.

Anthropic's agentic coding CLI, and the reference implementation of Agent Skills. Drop a skill folder into ~/.claude/skills and Claude Code loads it automatically whenever a task matches the skill's description. Claude Code docs

Inside SKILL.md

Written by tech-leads-club

Web quality audit

Comprehensive quality review based on Google Lighthouse audits. Covers Performance, Accessibility, SEO, and Best Practices across 150+ checks.

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)

Security:

  • HTTPS everywhere. No mixed content. HSTS enabled.
  • No vulnerable libraries. Keep dependencies updated.
  • CSP headers. Content Security Policy to prevent XSS.
  • No exposed source maps. In production builds.

Modern Standards:

  • No deprecated APIs. Replace document.write, synchronous XHR, etc.
  • Valid doctype. Use <!DOCTYPE html>.
  • Charset declared. <meta charset="UTF-8"> as first element in <head>.
  • No browser errors. Clean console. No CORS issues.

UX Patterns:

  • No intrusive interstitials. Especially on mobile.
  • Clear permission requests. Only ask when needed, with context.
  • No misleading buttons. Buttons do what they say.

Severity levels

LevelDescriptionAction
CriticalSecurity vulnerabilities, complete failuresFix immediately
HighCore Web Vitals failures, major a11y barriersFix before launch
MediumPerformance opportunities, SEO improvementsFix within sprint
LowMinor optimizations, code qualityFix when convenient

Audit output format

When performing an audit, structure findings as:

## Audit results

### Critical issues (X found)

- **[Category]** Issue description. File: `path/to/file.js:123`
  - **Impact:** Why this matters
  - **Fix:** Specific code change or recommendation

### High priority (X found)

...

### Summary

- Performance: X issues (Y critical)
- Accessibility: X issues (Y critical)
- SEO: X issues
- Best Practices: X issues

### Recommended priority

1. First fix this because...
2. Then address...
3. Finally optimize...

Quick checklist

Before every deploy

  • Core Web Vitals passing
  • No accessibility errors (axe/Lighthouse)
  • No console errors
  • HTTPS working
  • Meta tags present

Weekly review

  • Check Search Console for issues
  • Review Core Web Vitals trends
  • Update dependencies
  • Test with screen reader

Monthly deep dive

  • Full Lighthouse audit
  • Performance profiling
  • Accessibility audit with real users
  • SEO keyword review

References

For detailed guidelines on specific areas:

Frequently asked questions about Web Quality Audit

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