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):

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"