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
On-page SEO	~10%	✓

Technical SEO

Crawlability

robots.txt
Meta Robots
Canonical URLs

# /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

<!-- 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">

<!-- 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

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

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

<title>Page</title>
<title>Home</title>

<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

<meta name="description" content="">

<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

<h2>Welcome to Our Store</h2>
<h4>Products</h4>
<h1>Contact Us</h1>

<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

<img src="IMG_12345.jpg">

<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

<a href="/products">Click here</a>
<a href="/widgets">Read more</a>

<a href="/products/blue-widgets">Browse our blue widget collection</a>
<a href="/guides/widget-maintenance">Learn how to maintain your widgets</a>

Linking guidelines:

Descriptive anchor text with keywords
Link to relevant internal pages
Reasonable number of links per page
Fix broken links promptly
Use breadcrumbs for hierarchy

Structured Data (JSON-LD)

Organization

<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "Organization",
  "name": "Example Company",
  "url": "https://example.com",
  "logo": "https://example.com/logo.png",
  "sameAs": [
    "https://twitter.com/example",
    "https://linkedin.com/company/example"
  ],
  "contactPoint": {
    "@type": "ContactPoint",
    "telephone": "+1-555-123-4567",
    "contactType": "customer service"
  }
}
</script>

Article

<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "Article",
  "headline": "How to Choose the Right Widget",
  "description": "Complete guide to selecting widgets for your needs.",
  "image": "https://example.com/article-image.jpg",
  "author": {
    "@type": "Person",
    "name": "Jane Smith",
    "url": "https://example.com/authors/jane-smith"
  },
  "publisher": {
    "@type": "Organization",
    "name": "Example Blog",
    "logo": {
      "@type": "ImageObject",
      "url": "https://example.com/logo.png"
    }
  },
  "datePublished": "2024-01-15",
  "dateModified": "2024-01-20"
}
</script>

Product

<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "Product",
  "name": "Blue Widget Pro",
  "image": "https://example.com/blue-widget.jpg",
  "description": "Premium blue widget with advanced features.",
  "brand": {
    "@type": "Brand",
    "name": "WidgetCo"
  },
  "offers": {
    "@type": "Offer",
    "price": "49.99",
    "priceCurrency": "USD",
    "availability": "https://schema.org/InStock",
    "url": "https://example.com/products/blue-widget"
  },
  "aggregateRating": {
    "@type": "AggregateRating",
    "ratingValue": "4.8",
    "reviewCount": "1250"
  }
}
</script>

FAQ

<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "FAQPage",
  "mainEntity": [
    {
      "@type": "Question",
      "name": "What colors are available?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Our widgets come in blue, red, and green."
      }
    },
    {
      "@type": "Question",
      "name": "What is the warranty?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "All widgets include a 2-year warranty."
      }
    }
  ]
}
</script>

Breadcrumbs

<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "BreadcrumbList",
  "itemListElement": [
    {
      "@type": "ListItem",
      "position": 1,
      "name": "Home",
      "item": "https://example.com"
    },
    {
      "@type": "ListItem",
      "position": 2,
      "name": "Products",
      "item": "https://example.com/products"
    },
    {
      "@type": "ListItem",
      "position": 3,
      "name": "Blue Widgets",
      "item": "https://example.com/products/blue-widgets"
    }
  ]
}
</script>

Validation

Test structured data at:

Mobile SEO

Responsive Design

<meta name="viewport" content="width=1024">

<meta name="viewport" content="width=device-width, initial-scale=1">

Tap Targets

.small-link {
  padding: 4px;
  font-size: 12px;
}

.mobile-friendly-link {
  padding: 12px;
  font-size: 16px;
  min-height: 48px;
  min-width: 48px;
}

Font Sizes

body {
  font-size: 10px;
}

body {
  font-size: 16px;
  line-height: 1.5;
}

International SEO

Hreflang Tags

<!-- For multi-language sites -->
<link rel="alternate" hreflang="en" href="https://example.com/page">
<link rel="alternate" hreflang="es" href="https://example.com/es/page">
<link rel="alternate" hreflang="fr" href="https://example.com/fr/page">
<link rel="alternate" hreflang="x-default" href="https://example.com/page">

Language Declaration

<html lang="en">
<!-- or -->
<html lang="es-MX">

SEO Audit Checklist

Critical

High Priority

Medium Priority

Ongoing

Fix crawl errors in Search Console
Update sitemap when content changes
Monitor ranking changes
Check for broken links
Review Search Console insights

Tools

Tool	Use
Google Search Console	Monitor indexing, fix issues
Google PageSpeed Insights	Performance + Core Web Vitals
Rich Results Test	Validate structured data
Lighthouse	Full SEO audit
Screaming Frog	Crawl analysis

Overview

Audit Skills

Performance

Quality & Standards

SEO Optimization

SEO Optimization

SEO Fundamentals

Technical SEO

Crawlability

XML Sitemap

URL Structure

HTTPS & Security

On-Page SEO

Title Tags

Meta Descriptions

Heading Structure

Image SEO

Internal Linking

Structured Data (JSON-LD)

Organization

Article

Product

FAQ

Validation

Mobile SEO

Responsive Design

Tap Targets

Font Sizes

International SEO

Hreflang Tags

Language Declaration

SEO Audit Checklist

Critical

High Priority

Medium Priority

Ongoing

Tools

External Resources

Core Web Vitals

Web Quality Audit

​SEO Optimization

​SEO Fundamentals

​Technical SEO

​Crawlability

​XML Sitemap

​URL Structure

​HTTPS & Security

​On-Page SEO

​Title Tags

​Meta Descriptions

​Heading Structure

​Image SEO

​Internal Linking

​Structured Data (JSON-LD)

​Organization

​Article

​Product

​FAQ

​Breadcrumbs

​Validation

​Mobile SEO

​Responsive Design

​Tap Targets

​Font Sizes

​International SEO

​Hreflang Tags

​Language Declaration

​SEO Audit Checklist

​Critical

​High Priority

​Medium Priority

​Ongoing

​Tools

​External Resources

Core Web Vitals

Web Quality Audit

SEO Optimization

SEO Fundamentals

Technical SEO

Crawlability

XML Sitemap

URL Structure

HTTPS & Security

On-Page SEO

Title Tags

Meta Descriptions

Heading Structure

Image SEO

Internal Linking

Structured Data (JSON-LD)

Organization

Article

Product

FAQ

Breadcrumbs

Validation

Mobile SEO

Responsive Design

Tap Targets

Font Sizes

International SEO

Hreflang Tags

Language Declaration

SEO Audit Checklist

Critical

High Priority

Medium Priority

Ongoing

Tools

External Resources