/seo

name: seo
description: Optimize for search engine visibility and ranking. Use when asked to "improve SEO", "optimize for search", "fix meta tags", "add structured data", "sitemap optimization", or "search engine optimization". Do NOT use for accessibility (use web-accessibility), performance (use core-web-vitals), or comprehensive site audits covering multiple areas (use web-quality-audit).
license: MIT
metadata:
  author: web-quality-skills
  version: '1.0'

SEO optimization

Search engine optimization based on Lighthouse SEO audits and Google Search guidelines. Focus on technical SEO, on-page optimization, and structured data.

SEO fundamentals

Search ranking factors (approximate influence):

| Factor | Influence | This Skill | | --------------------------------- | --------- | -------------------------------------------------- | | Content quality & relevance | ~40% | Partial (structure) | | Backlinks & authority | ~25% | ✗ | | Technical SEO | ~15% | ✓ | | Page experience (Core Web Vitals) | ~10% | See [Core Web Vitals](../core-web-vitals/SKILL.md) | | On-page SEO | ~10% | ✓ |

---

Technical SEO

Crawlability

**robots.txt:**

# /robots.txt
User-agent: *
Allow: /

# Block admin/private areas
Disallow: /admin/
Disallow: /api/
Disallow: /private/

# Don't block resources needed for rendering
# ❌ Disallow: /static/

Sitemap: https://example.com/sitemap.xml

**Meta robots:**

<!-- Default: indexable, followable -->
<meta name="robots" content="index, follow" />

<!-- Noindex specific pages -->
<meta name="robots" content="noindex, nofollow" />

<!-- Indexable but don't follow links -->
<meta name="robots" content="index, nofollow" />

<!-- Control snippets -->
<meta name="robots" content="max-snippet:150, max-image-preview:large" />

**Canonical URLs:**

<!-- Prevent duplicate content issues -->
<link rel="canonical" href="https://example.com/page" />

<!-- Self-referencing canonical (recommended) -->
<link rel="canonical" href="https://example.com/current-page" />

<!-- For paginated content -->
<link rel="canonical" href="https://example.com/products" />
<!-- Or use rel="prev" / rel="next" for explicit pagination -->

XML sitemap

<?xml version="1.0" encoding="UTF-8"?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
  <url>
    <loc>https://example.com/</loc>
    <lastmod>2024-01-15</lastmod>
    <changefreq>daily</changefreq>
    <priority>1.0</priority>
  </url>
  <url>
    <loc>https://example.com/products</loc>
    <lastmod>2024-01-14</lastmod>
    <changefreq>weekly</changefreq>
    <priority>0.8</priority>
  </url>
</urlset>

**Sitemap best practices:**

• Maximum 50,000 URLs or 50MB per sitemap
• Use sitemap index for larger sites
• Include only canonical, indexable URLs
• Update `lastmod` when content changes
• Submit to Google Search Console

URL structure

✅ Good URLs:
https://example.com/products/blue-widget
https://example.com/blog/how-to-use-widgets

❌ Poor URLs:
https://example.com/p?id=12345
https://example.com/products/item/category/subcategory/blue-widget-2024-sale-discount

**URL guidelines:**

• Use hyphens, not underscores
• Lowercase only
• Keep short (< 75 characters)
• Include target keywords naturally
• Avoid parameters when possible
• Use HTTPS always

HTTPS & security

<!-- Ensure all resources use HTTPS -->
<img src="https://example.com/image.jpg" />

<!-- Not: -->
<img src="http://example.com/image.jpg" />

**Security headers for SEO trust signals:**

Strict-Transport-Security: max-age=31536000; includeSubDomains
X-Content-Type-Options: nosniff
X-Frame-Options: DENY

---

On-page SEO

Title tags

<!-- ❌ Missing or generic -->
<title>Page</title>
<title>Home</title>

<!-- ✅ Descriptive with primary keyword -->
<title>Blue Widgets for Sale | Premium Quality | Example Store</title>

**Title tag guidelines:**

• 50-60 characters (Google truncates ~60)
• Primary keyword near the beginning
• Unique for every page
• Brand name at end (unless homepage)
• Action-oriented when appropriate

Meta descriptions

<!-- ❌ Missing or duplicate -->
<meta name="description" content="" />

<!-- ✅ Compelling and unique -->
<meta
  name="description"
  content="Shop premium blue widgets with free shipping. 30-day returns. Rated 4.9/5 by 10,000+ customers. Order today and save 20%."
/>

**Meta description guidelines:**

• 150-160 characters
• Include primary keyword naturally
• Compelling call-to-action
• Unique for every page
• Matches page content

Heading structure

<!-- ❌ Poor structure -->
<h2>Welcome to Our Store</h2>
<h4>Products</h4>
<h1>Contact Us</h1>

<!-- ✅ Proper hierarchy -->
<h1>Blue Widgets - Premium Quality</h1>
<h2>Product Features</h2>
<h3>Durability</h3>
<h3>Design</h3>
<h2>Customer Reviews</h2>
<h2>Pricing</h2>

**Heading guidelines:**

• Single `<h1>` per page (the main topic)
• Logical hierarchy (don't skip levels)
• Include keywords naturally
• Descriptive, not generic

Image SEO

<!-- ❌ Poor image SEO -->
<img src="IMG_12345.jpg" />

<!-- ✅ Optimized image -->
<img
  src="blue-widget-product-photo.webp"
  alt="Blue widget with chrome finish, side view showing control panel"
  width="800"
  height="600"
  loading="lazy"
/>

**Image guidelines:**

• Descriptive filenames with keywords
• Alt text describes the image content
• Compressed and properly sized
• WebP/AVIF with fallbacks
• Lazy load below-fold images

Internal linking

<!-- ❌ Non-descriptive -->
<a href="/products">Click here</a>
<a href="/widgets">Read more</a>

<!-- ✅ Descriptive