osvaldovegacasanova/doe

Expert On-Site SEO Knowledge Base

Purpose: AI agent reference for on-site SEO optimization Scope: Technology-agnostic SEO principles Level: Expert (technical + strategic)

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1. FOUNDATION - SEO FUNDAMENTALS

How Search Engines Work

Crawling → Indexing → Ranking

1. Crawling: Bots (Googlebot) discover pages via links and sitemaps
2. Indexing: Content analyzed, stored in search index
3. Ranking: Algorithm determines relevance and authority for queries

Key Concepts:

• PageRank: Link equity flows through internal/external links
• Render Queue: JavaScript-heavy sites may be indexed in two passes
• Crawl Budget: Limited resources per site (optimize for important pages)

On-Site vs Off-Site SEO

On-Site SEO (you control):

• Technical infrastructure (speed, mobile, structure)
• Content quality and optimization
• Internal linking
• Meta tags and structured data
• User experience signals

Off-Site SEO (external):

• Backlinks from other domains
• Brand mentions and citations
• Social signals
• Domain authority accumulation

Critical Metrics

| Metric | Target | Impact | |--------|--------|--------| | Organic Traffic | Increasing trend | Direct business value | | Keyword Rankings | Top 3 positions | 75%+ of clicks | | CTR from SERPs | 3-5%+ average | Indicates relevance | | Core Web Vitals | All green | Ranking factor | | Indexed Pages | Match site size | Crawlability health | | Dwell Time | 2+ minutes | Engagement signal |

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2. TECHNICAL SEO

Site Architecture

URL Structure Best Practices:

✅ Good:
https://example.com/services/seo/
https://example.com/blog/on-site-seo-guide/
https://example.com/products/shoes/running/

❌ Bad:
https://example.com/page?id=123&session=xyz
https://example.com/index.php?cat=5
https://example.com////multiple-slashes

Rules:

• Use semantic, readable URLs
• Hyphens for word separation (not underscores)
• Lowercase only
• Consistent trailing slash policy
• Avoid parameters when possible

Internal Linking Strategy:

• Hub & Spoke: Pillar pages link to cluster content
• Contextual Links: Anchor text describes destination
• Depth Rule: Important pages ≤3 clicks from homepage
• Orphan Prevention: All pages have ≥1 internal link
• Link Equity: Distribute authority strategically

Robots.txt

Purpose: Control crawler access and crawl budget

# Allow all crawlers
User-agent: *
Allow: /

# Block admin and private areas
Disallow: /admin/
Disallow: /private/
Disallow: /cart/
Disallow: /checkout/

# Don't block CSS/JS (Google needs them)
Allow: /assets/
Allow: /*.css$
Allow: /*.js$

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

# Crawl delay (use sparingly)
Crawl-delay: 1

Common Mistakes:

• Blocking CSS/JS files (prevents proper rendering)
• Blocking entire site with Disallow: /
• Conflicting with meta robots tags

Indexing Control

Meta Robots Tags:

<!-- Index page, follow links (default) -->
<meta name="robots" content="index, follow">

<!-- Don't index, but follow links -->
<meta name="robots" content="noindex, follow">

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

<!-- Block everything -->
<meta name="robots" content="noindex, nofollow">

<!-- Prevent snippet -->
<meta name="robots" content="nosnippet">

<!-- Max snippet length -->
<meta name="robots" content="max-snippet:160">

Canonical URLs:

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

<!-- Cross-page canonical (duplicate content) -->
<link rel="canonical" href="https://example.com/original-page/">

Rules:

• Every page needs canonical tag
• Use absolute URLs (not relative)
• HTTPS only
• Match your preferred domain (www vs non-www)
• Avoid canonical chains (A→B→C)

Redirects:

• 301 Permanent: Page moved forever (passes 90-99% link equity)
• 302 Temporary: Page moved temporarily (no link equity)
• Avoid redirect chains (max 1 redirect)
• Never redirect to redirected URLs

Site Speed & Core Web Vitals

Core Web Vitals Thresholds: | Metric | Good | Needs Improvement | Poor | |--------|------|-------------------|------| | LCP (Largest Contentful Paint) | <2.5s | 2.5-4.0s | >4.0s | | FID (First Input Delay) | <100ms | 100-300ms | >300ms | | CLS (Cumulative Layout Shift) | <0.1 | 0.1-0.25 | >0.25 |

Optimization Techniques:

Images:

<!-- Modern formats -->
<picture>
  <source srcset="image.avif" type="image/avif">
  <source srcset="image.webp" type="image/webp">
  <img src="image.jpg" alt="Description" loading="lazy" width="800" height="600">
</picture>

<!-- Responsive images -->
<img
  srcset="small.jpg 400w, medium.jpg 800w, large.jpg 1200w"
  sizes="(max-width: 600px) 400px, (max-width: 1200px) 800px, 1200px"
  src="medium.jpg"
  alt="Description"
  loading="lazy"
>

JavaScript/CSS:

<!-- Defer non-critical JS -->
<script src="analytics.js" defer></script>

<!-- Async independent scripts -->
<script src="ads.js" async></script>

<!-- Preload critical resources -->
<link rel="preload" href="font.woff2" as="font" type="font/woff2" crossorigin>

<!-- Critical CSS inline, defer rest -->
<style>/* Critical CSS here */</style>
<link rel="stylesheet" href="styles.css" media="print" onload="this.media='all'">

Server Performance:

• TTFB (Time to First Byte) <600ms
• Use CDN for static assets
• Enable compression (Gzip/Brotli)
• Implement caching headers
• Consider SSR/SSG for faster initial load

Mobile-First Optimization

Critical: Google uses mobile version for indexing (since 2021)

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

Requirements:

• Responsive design (single URL, adaptive CSS)
• Touch-friendly tap targets (≥48px)
• Readable text without zooming (≥16px base)
• No horizontal scrolling
• Fast mobile performance (even more critical than desktop)

HTTPS & Security

<!-- Force HTTPS -->
<meta http-equiv="Content-Security-Policy" content="upgrade-insecure-requests">

<!-- HSTS header (server-side) -->
Strict-Transport-Security: max-age=31536000; includeSubDomains

Requirements:

• Valid SSL certificate
• No mixed content (HTTP resources on HTTPS pages)
• HTTPS is a ranking signal

Structured Data (Schema.org)

Prefer JSON-LD (easier to manage, Google recommended):

<!-- Organization -->
<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "Organization",
  "name": "Company Name",
  "url": "https://example.com",
  "logo": "https://example.com/logo.png",
  "sameAs": [
    "https://facebook.com/company",
    "https://twitter.com/company"
  ],
  "contactPoint": {
    "@type": "ContactPoint",
    "telephone": "+1-555-1234",
    "contactType": "Customer Service"
  }
}
</script>

<!-- LocalBusiness -->
<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "LocalBusiness",
  "name": "Business Name",
  "address": {
    "@type": "PostalAddress",
    "streetAddress": "123 Main St",
    "addressLocality": "City",
    "addressRegion": "State",
    "postalCode": "12345",
    "addressCountry": "US"
  },
  "geo": {
    "@type": "GeoCoordinates",
    "latitude": 40.7128,
    "longitude": -74.0060
  },
  "telephone": "+1-555-1234",
  "openingHours": "Mo-Fr 09:00-17:00"
}
</script>

<!-- Article/BlogPosting -->
<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "BlogPosting",
  "headline": "Article Title",
  "image": "https://example.com/image.jpg",
  "datePublished": "2024-01-15T08:00:00+00:00",
  "dateModified": "2024-01-20T10:30:00+00:00",
  "author": {
    "@type": "Person",
    "name": "Author Name"
  },
  "publisher": {
    "@type": "Organization",
    "name": "Publisher Name",
    "logo": {
      "@type": "ImageObject",
      "url": "https://example.com/logo.png"
    }
  },
  "description": "Article description",
  "mainEntityOfPage": {
    "@type": "WebPage",
    "@id": "https://example.com/article/"
  }
}
</script>

<!-- BreadcrumbList -->
<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": "Category",
      "item": "https://example.com/category/"
    },
    {
      "@type": "ListItem",
      "position": 3,
      "name": "Page",
      "item": "https://example.com/category/page/"
    }
  ]
}
</script>

<!-- FAQPage -->
<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "FAQPage",
  "mainEntity": [
    {
      "@type": "Question",
      "name": "Question text?",
      "acceptedAnswer": {
        "@type": "Answer",
        "text": "Answer text here."
      }
    }
  ]
}
</script>

<!-- Product (E-commerce) -->
<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "Product",
  "name": "Product Name",
  "image": "https://example.com/product.jpg",
  "description": "Product description",
  "brand": {
    "@type": "Brand",
    "name": "Brand Name"
  },
  "offers": {
    "@type": "Offer",
    "price": "99.99",
    "priceCurrency": "USD",
    "availability": "https://schema.org/InStock",
    "url": "https://example.com/product/"
  },
  "aggregateRating": {
    "@type": "AggregateRating",
    "ratingValue": "4.5",
    "reviewCount": "127"
  }
}
</script>

Validation: Use Google Rich Results Test (search.google.com/test/rich-results)

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3. CONTENT OPTIMIZATION

Keyword Research

Search Intent Types:

1. Informational: "how to optimize SEO"
2. Navigational: "Google Search Console login"
3. Transactional: "buy running shoes online"
4. Commercial: "best CRM software 2024"

Selection Criteria:

• Search volume vs competition balance
• Intent matches content type
• Business relevance
• Long-tail opportunities (3-5+ words, lower competition)

On-Page Elements

Title Tags:

<!-- Optimal structure -->
<title>Primary Keyword - Secondary Keyword | Brand Name</title>

<!-- Guidelines -->
- Length: 50-60 characters (desktop), 78 (mobile)
- Primary keyword near beginning
- Unique per page
- Compelling (improves CTR)
- Brand name at end (or omit on non-homepage)

Meta Descriptions:

<meta name="description" content="Compelling description that includes primary keyword, answers search intent, and includes a call-to-action. Keep it natural and engaging.">

<!-- Guidelines -->
- Length: 150-160 characters
- Include primary + secondary keywords naturally
- Call-to-action when appropriate
- Unique per page
- NOT a direct ranking factor (but impacts CTR)

Heading Hierarchy:

<h1>Main Page Topic - Only ONE per page</h1>
  <h2>Major Section 1</h2>
    <h3>Subsection 1.1</h3>
    <h3>Subsection 1.2</h3>
  <h2>Major Section 2</h2>
    <h3>Subsection 2.1</h3>
      <h4>Detail 2.1.1</h4>

Rules:

• One H1 per page (main topic)
• Don't skip levels (H2 → H4 without H3)
• Include keywords naturally
• Use for structure, not styling

Body Content:

• Keyword Density: 1-2% (avoid stuffing)
• LSI Keywords: Related terms (Google understands context)
• Length: Quality > quantity, but 1500+ words often rank well
• Readability: Short paragraphs, clear language (Flesch score 60+)
• E-E-A-T: Experience, Expertise, Authoritativeness, Trustworthiness

Image Optimization:

<img
  src="descriptive-keyword-filename.webp"
  alt="Descriptive text that includes keyword naturally"
  width="800"
  height="600"
  loading="lazy"
>

<!-- Guidelines -->
- Descriptive filenames (seo-audit-checklist.jpg not IMG_1234.jpg)
- Alt text describes image (screen readers + SEO)
- Specify dimensions (prevents CLS)
- Compress images (WebP/AVIF formats)
- Lazy load below fold

Internal Linking:

<!-- Good anchor text -->
<a href="/services/technical-seo/">Learn about technical SEO audits</a>

<!-- Bad anchor text -->
<a href="/services/technical-seo/">click here</a>

Rules:

• Descriptive anchor text (not "click here")
• Link to relevant content
• Vary anchor text (not same phrase every time)
• 2-5 internal links per 1000 words

External Links:

<!-- Link to authoritative sources -->
<a href="https://developers.google.com/search" rel="noopener">Google Search Central</a>

<!-- Paid/sponsored links -->
<a href="https://example.com" rel="sponsored">Partner Site</a>

<!-- User-generated content -->
<a href="https://example.com" rel="ugc">User Comment Link</a>

<!-- Untrusted content -->
<a href="https://example.com" rel="nofollow">Untrusted Link</a>

Content Freshness

Signals:

• Publish date (structured data)
• Last modified date (HTTP header + schema)
• Regular content updates
• New content publishing frequency

Strategy:

• Evergreen Content: Update annually with new data
• Timely Content: Date in URL/title when relevant
• Historical Optimization: Update old posts (change dates)
• Content Pruning: Remove/consolidate thin/outdated pages

Duplicate Content

Solutions:

<!-- Canonical consolidation -->
<link rel="canonical" href="https://example.com/original/">

<!-- For parameters -->
Original: https://example.com/product/?color=red
Canonical: https://example.com/product/

<!-- For pagination -->
Page 2: <link rel="canonical" href="https://example.com/category/?page=2">
(Each page is self-canonical, not to page 1)

Prevention:

• Use canonical tags consistently
• 301 redirect moved content
• Handle URL parameters in Search Console
• Avoid session IDs in URLs
• Use hreflang for multilingual (not canonical)

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4. USER EXPERIENCE & SEO

UX Signals Impacting Rankings

| Signal | What It Measures | How to Improve | |--------|------------------|----------------| | Dwell Time | Time on page before returning to SERPs | Engaging content, clear layout | | Bounce Rate | % who leave after one page | Improve relevance, internal links | | Pages/Session | Exploration depth | Strong internal linking | | Pogo-Sticking | Quick back-to-SERP bounces | Match search intent better | | Return Visitors | Repeat traffic | Quality content, brand building |

Navigation Best Practices

• Clear hierarchy: Main nav with 5-7 categories max
• Mega menus: For large sites (organize by category)
• Breadcrumbs: Show location (+ BreadcrumbList schema)
• Search functionality: For 100+ pages
• Footer nav: Secondary links, sitemap link
• Custom 404s: Helpful (search box, popular pages, contact)

Readability & Formatting

<!-- Scannable content -->
<p>Short paragraphs (2-4 sentences max).</p>

<ul>
  <li>Bullet points for lists</li>
  <li>Numbered lists for steps</li>
</ul>

<blockquote>
  Quotes for emphasis and authority
</blockquote>

<strong>Bold for important terms</strong>
<em>Italics for emphasis</em>

<!-- Tables for data -->
<table>
  <thead>
    <tr><th>Feature</th><th>Value</th></tr>
  </thead>
  <tbody>
    <tr><td>Data</td><td>Info</td></tr>
  </tbody>
</table>

Typography:

• Font size ≥16px (mobile)
• Line height 1.5-1.8
• Contrast ratio ≥4.5:1 (WCAG AA)
• Max line length ~70 characters
• Generous white space

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5. INTERNATIONAL & MULTILINGUAL SEO

Hreflang Implementation

Purpose: Tell Google which language/region version to show

<!-- English US version -->
<link rel="alternate" hreflang="en-us" href="https://example.com/en-us/">

<!-- Spanish Spain -->
<link rel="alternate" hreflang="es-es" href="https://example.com/es-es/">

<!-- Spanish Chile -->
<link rel="alternate" hreflang="es-cl" href="https://example.com/es-cl/">

<!-- Default fallback -->
<link rel="alternate" hreflang="x-default" href="https://example.com/">

<!-- Self-referencing (required) -->
<link rel="alternate" hreflang="en-us" href="https://example.com/en-us/">

Rules:

• ISO 639-1 language codes (en, es, fr)
• ISO 3166-1 Alpha 2 region codes (US, ES, CL)
• All versions must link to each other (reciprocal)
• Include self-referencing tag
• Use x-default for global/language selector
• Can be in HTML head or XML sitemap

Common Mistakes:

• Missing reciprocal tags
• Incorrect language/region codes
• Mixing hreflang with canonical (use both, don't conflict)

URL Structure Options

| Method | Example | Pros | Cons | |--------|---------|------|------| | ccTLD | example.fr | Strongest geo-signal | Expensive, complex management | | Subdomain | fr.example.com | Easy to set up | Treated as separate site | | Subdirectory | example.com/fr/ | Consolidates authority | Weaker geo-signal | | Parameters | example.com?lang=fr | Easiest | Poor UX, weak signal |

Recommendation: Subdirectories for most cases (balance of SEO + management)

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6. E-COMMERCE SEO

Product Pages

<!-- Title: Product Name + Key Attribute -->
<title>Nike Air Max 90 - Men's Running Shoes | Store Name</title>

<!-- Unique descriptions (never use manufacturer copy) -->
<p>Custom product description highlighting unique value...</p>

<!-- Product Schema -->
<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "Product",
  "name": "Nike Air Max 90",
  "image": ["https://example.com/product1.jpg", "https://example.com/product2.jpg"],
  "description": "Product description",
  "sku": "0446310786",
  "mpn": "925807",
  "brand": {
    "@type": "Brand",
    "name": "Nike"
  },
  "offers": {
    "@type": "Offer",
    "url": "https://example.com/product/",
    "priceCurrency": "USD",
    "price": "119.99",
    "priceValidUntil": "2024-12-31",
    "availability": "https://schema.org/InStock",
    "itemCondition": "https://schema.org/NewCondition"
  },
  "aggregateRating": {
    "@type": "AggregateRating",
    "ratingValue": "4.4",
    "reviewCount": "89"
  },
  "review": [{
    "@type": "Review",
    "reviewRating": {
      "@type": "Rating",
      "ratingValue": "5"
    },
    "author": {
      "@type": "Person",
      "name": "John Doe"
    },
    "reviewBody": "Great shoes, very comfortable!"
  }]
}
</script>

Requirements:

• High-quality images (multiple angles)
• Unique descriptions (500+ words for competitive products)
• Reviews and ratings (schema + visible)
• Clear pricing and availability
• Structured data for rich snippets
• FAQ section for common questions

Category Pages

<h1>Men's Running Shoes</h1>

<!-- Category description (200-500 words) -->
<div class="category-description">
  <p>Keyword-rich description at top or bottom of page...</p>
</div>

<!-- Products grid -->
<div class="products">
  <!-- Product listings -->
</div>

Faceted Navigation (filters/sorting):

<!-- Use canonical to prevent duplicate content -->
Filtered URL: example.com/shoes/?color=red&size=10
Canonical: <link rel="canonical" href="https://example.com/shoes/">

<!-- Or allow indexing if significant search volume -->
Filtered URL: example.com/shoes/red/
(Self-canonical, unique content)

E-commerce Technical Issues

Out of Stock:

<!-- Keep page indexed, update schema -->
"offers": {
  "@type": "Offer",
  "availability": "https://schema.org/OutOfStock"
}

Product Variants:

<!-- Option 1: Canonical to main product -->
example.com/shirt/blue/ → canonical → example.com/shirt/

<!-- Option 2: Separate pages if significant differences -->
example.com/shirt/blue/ (self-canonical)

Pagination:

<!-- Each page is self-canonical -->
<link rel="canonical" href="https://example.com/category/?page=2">

<!-- No rel=prev/next (deprecated by Google) -->

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7. LOCAL SEO (ON-SITE)

NAP Consistency

NAP = Name, Address, Phone

<!-- Must match EXACTLY across all pages -->
<footer>
  <p>Business Name</p>
  <p>123 Main Street, Suite 100</p>
  <p>City, State 12345</p>
  <p>(555) 123-4567</p>
</footer>

<!-- Schema.org -->
<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "LocalBusiness",
  "name": "Business Name",
  "address": {
    "@type": "PostalAddress",
    "streetAddress": "123 Main Street, Suite 100",
    "addressLocality": "City",
    "addressRegion": "State",
    "postalCode": "12345",
    "addressCountry": "US"
  },
  "telephone": "+15551234567"
}
</script>

Location Pages

Multi-location businesses:

example.com/locations/new-york/
example.com/locations/chicago/
example.com/locations/los-angeles/

Requirements:

• Unique content per location (not templated)
• Local keywords (city/neighborhood names)
• Embedded Google Map
• Local testimonials
• Service area description
• Geo-coordinates in schema

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8. BLOG & CONTENT MARKETING SEO

Blog Architecture

example.com/blog/ (index)
example.com/blog/category/seo/
example.com/blog/category/content-marketing/
example.com/blog/author/john-smith/
example.com/blog/2024/01/article-title/

Best Practices:

• Clear category structure (noindex tag archives if thin)
• Author pages with bios (builds E-E-A-T)
• Related posts section (internal linking)
• Tag pages (sparingly, avoid thin content)

Content Clusters

Model: Pillar + Cluster

Pillar: example.com/complete-seo-guide/ (5000+ words)
├─ Cluster: example.com/technical-seo/
├─ Cluster: example.com/on-page-seo/
├─ Cluster: example.com/link-building/
└─ Cluster: example.com/local-seo/

Internal Linking:

• Clusters link to pillar
• Pillar links to all clusters
• Clusters link to related clusters
• Use descriptive anchor text

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9. ADVANCED TECHNIQUES

JavaScript SEO

Rendering Methods:

1. Client-Side Rendering (CSR): React/Vue default (SEO challenges)
2. Server-Side Rendering (SSR): HTML generated on server (SEO friendly)
3. Static Site Generation (SSG): Pre-built HTML (best for SEO)

Google's Two-Pass Indexing:

1. Initial HTML crawl
2. Render queue (may take hours/days)

Testing:

# View as Googlebot
# Google Search Console → URL Inspection → View Crawled Page

# Or fetch with user-agent
curl -A "Googlebot" https://example.com/

Meta Tag Management (SPA):

// React Helmet example
<Helmet>
  <title>{dynamicTitle}</title>
  <meta name="description" content={dynamicDescription} />
  <link rel="canonical" href={dynamicCanonical} />
</Helmet>

Video SEO

<!-- Video Schema -->
<script type="application/ld+json">
{
  "@context": "https://schema.org",
  "@type": "VideoObject",
  "name": "Video Title",
  "description": "Video description",
  "thumbnailUrl": "https://example.com/thumbnail.jpg",
  "uploadDate": "2024-01-15T08:00:00+08:00",
  "duration": "PT1M33S",
  "contentUrl": "https://example.com/video.mp4",
  "embedUrl": "https://example.com/embed/video"
}
</script>

Best Practices:

• Provide transcript (full text on page)
• Captions/subtitles file
• Descriptive title and description
• High-quality thumbnail
• Video sitemap (optional)

Voice Search Optimization

Strategy:

• Target question-based queries ("How do I...", "What is...")
• Natural language content
• FAQ schema for featured snippets
• Local SEO (many voice searches are local)
• Page speed (voice prioritizes fast sites)

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10. MONITORING & ANALYSIS

Essential Tools

Google Search Console:

• Performance (clicks, impressions, CTR, position)
• Index coverage (errors, warnings, valid pages)
• Mobile usability
• Core Web Vitals
• Manual actions
• Security issues

Google Analytics 4:

• Organic traffic sources
• Landing pages performance
• Conversion tracking
• Behavior flow
• Engagement metrics

Third-Party:

• SEMrush/Ahrefs: Keyword tracking, backlinks, competitor analysis
• Screaming Frog: Technical audits (crawl site like Googlebot)
• PageSpeed Insights: Performance metrics
• Schema Validator: Structured data testing

Key Performance Indicators

| KPI | Target | Frequency | |-----|--------|-----------| | Organic Traffic | Month-over-month growth | Monthly | | Keyword Rankings | Top 3 for priority keywords | Weekly | | CTR from SERPs | 3-5% average | Monthly | | Conversion Rate | Varies by industry | Monthly | | Core Web Vitals | All green | Weekly | | Indexed Pages | Match total pages | Weekly | | Crawl Errors | Zero critical | Weekly |

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11. COMMON MISTAKES

Technical Mistakes

❌ Blocking CSS/JS in robots.txt

# Bad
Disallow: /*.css$
Disallow: /*.js$

# Good
Allow: /*.css$
Allow: /*.js$

❌ Redirect Chains

example.com/old → example.com/temp → example.com/new
# Fix: Direct redirect
example.com/old → example.com/new

❌ Mixed HTTP/HTTPS

<!-- Bad: HTTP resource on HTTPS page -->
<img src="http://example.com/image.jpg">

<!-- Good -->
<img src="https://example.com/image.jpg">

❌ Missing Canonical Tags

<!-- Every page needs this -->
<link rel="canonical" href="https://example.com/page/">

Content Mistakes

❌ Keyword Stuffing

Bad: "SEO services, best SEO services, affordable SEO services, SEO services company"
Good: "Professional SEO services to improve your search rankings"

❌ Duplicate Title Tags

Bad: All pages have title "Company Name"
Good: Each page has unique, descriptive title

❌ Thin Content

Bad: 100-word product descriptions
Good: 500+ words with details, benefits, FAQ

❌ Generic Meta Descriptions

Bad: "Welcome to our website. We offer services."
Good: "Get expert SEO audits with detailed recommendations. Improve rankings in 30 days. Free consultation."

UX Mistakes

❌ Intrusive Interstitials

• Full-screen popups on mobile (Google penalty)
• Fix: Use banners or delayed popups

❌ Poor Mobile Experience

• Small text, horizontal scrolling
• Fix: Responsive design, mobile testing

❌ Slow Page Speed

• 5+ second load times
• Fix: Image optimization, caching, CDN

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12. SEO CHECKLIST

Pre-Launch Checklist

Technical:

• [ ] Robots.txt configured (allows important pages)
• [ ] XML sitemap generated and submitted
• [ ] All pages have unique title tags (50-60 chars)
• [ ] All pages have unique meta descriptions (150-160 chars)
• [ ] Canonical URLs set correctly on every page
• [ ] Trailing slash policy consistent
• [ ] HTTPS enabled (valid SSL certificate)
• [ ] No mixed HTTP/HTTPS content
• [ ] 301 redirects for moved pages
• [ ] Custom 404 error page
• [ ] Favicon configured

Performance:

• [ ] Core Web Vitals in green zone (LCP <2.5s, FID <100ms, CLS <0.1)
• [ ] Images optimized (WebP/AVIF, lazy loading)
• [ ] JavaScript/CSS minified and compressed
• [ ] CDN configured for static assets
• [ ] Caching headers implemented

Content:

• [ ] H1 on every page (one per page)
• [ ] Logical heading hierarchy (H1→H2→H3)
• [ ] Alt text on all images
• [ ] Internal links with descriptive anchors
• [ ] No broken links (404s)

Mobile:

• [ ] Mobile-responsive design verified
• [ ] Viewport meta tag configured
• [ ] Touch-friendly elements (≥48px)
• [ ] Readable text (≥16px)
• [ ] Mobile page speed optimized

Structured Data:

• [ ] Organization schema on homepage
• [ ] BreadcrumbList on all pages
• [ ] Product schema (if e-commerce)
• [ ] Article/BlogPosting schema (if blog)
• [ ] LocalBusiness schema (if local)
• [ ] All schema validated (no errors)

Analytics:

• [ ] Google Search Console verified
• [ ] Google Analytics installed
• [ ] Conversion tracking configured
• [ ] Search Console sitemap submitted

Ongoing Optimization

Monthly:

• [ ] Review organic traffic trends
• [ ] Check keyword ranking changes
• [ ] Monitor Core Web Vitals
• [ ] Review Search Console errors
• [ ] Publish new content (2-4+ posts)
• [ ] Update old content (1-2 posts)

Quarterly:

• [ ] Full technical audit (Screaming Frog)
• [ ] Broken link check
• [ ] Competitor analysis
• [ ] Content gap analysis
• [ ] Backlink profile review

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13. ALGORITHM UPDATES

Major Google Updates (Historical)

| Year | Update | Focus | |------|--------|-------| | 2011 | Panda | Content quality (thin content penalty) | | 2012 | Penguin | Link spam (unnatural backlinks) | | 2013 | Hummingbird | Semantic search (meaning vs keywords) | | 2015 | Mobile-Friendly | Mobile usability (ranking factor) | | 2015 | RankBrain | Machine learning (query interpretation) | | 2018 | Medic | E-A-T for YMYL sites (health, finance) | | 2019 | BERT | Natural language processing (context) | | 2021 | Page Experience | Core Web Vitals (UX ranking factor) | | 2022 | Helpful Content | Reward people-first content | | 2023 | Core Updates | Multiple ranking factors (ongoing) |

Staying Current

Official Sources:

• Google Search Central Blog: developers.google.com/search/blog
• @searchliaison on Twitter
• Google Search Central YouTube

Industry News:

• Search Engine Journal
• Search Engine Land
• Moz Blog
• Ahrefs Blog

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14. QUICK REFERENCE

HTML Template

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">

  <!-- Primary Meta Tags -->
  <title>Primary Keyword - Secondary Keyword | Brand</title>
  <meta name="description" content="Compelling 150-160 character description with keywords and CTA.">
  <link rel="canonical" href="https://example.com/page/">

  <!-- Open Graph / Facebook -->
  <meta property="og:type" content="website">
  <meta property="og:url" content="https://example.com/page/">
  <meta property="og:title" content="Title for social sharing">
  <meta property="og:description" content="Description for social sharing">
  <meta property="og:image" content="https://example.com/image.jpg">

  <!-- Twitter -->
  <meta name="twitter:card" content="summary_large_image">
  <meta name="twitter:url" content="https://example.com/page/">
  <meta name="twitter:title" content="Title for Twitter">
  <meta name="twitter:description" content="Description for Twitter">
  <meta name="twitter:image" content="https://example.com/image.jpg">

  <!-- Favicon -->
  <link rel="icon" type="image/png" href="/favicon.png">

  <!-- CSS -->
  <link rel="stylesheet" href="/styles.css">

  <!-- Structured Data -->
  <script type="application/ld+json">
  {
    "@context": "https://schema.org",
    "@type": "WebPage",
    "name": "Page Name",
    "description": "Page description",
    "url": "https://example.com/page/"
  }
  </script>
</head>
<body>
  <!-- Content here -->
</body>
</html>

robots.txt Template

User-agent: *
Allow: /
Disallow: /admin/
Disallow: /private/
Disallow: /cart/
Disallow: /checkout/
Disallow: /search?
Allow: /*.css$
Allow: /*.js$

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

.htaccess (Apache)

# Force HTTPS
RewriteEngine On
RewriteCond %{HTTPS} off
RewriteRule ^(.*)$ https://%{HTTP_HOST}/$1 [L,R=301]

# Force www (or non-www)
RewriteCond %{HTTP_HOST} !^www\.
RewriteRule ^(.*)$ https://www.%{HTTP_HOST}/$1 [L,R=301]

# Trailing slash redirect
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_URI} !(.*)/$
RewriteRule ^(.*)$ https://%{HTTP_HOST}/$1/ [L,R=301]

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15. E-E-A-T PRINCIPLES

Experience, Expertise, Authoritativeness, Trustworthiness

Critical for YMYL (Your Money Your Life) sites:

• Health, medical, safety
• Financial advice
• Legal information
• News and current events

How to Demonstrate E-E-A-T:

Experience:

• First-hand product reviews
• Case studies with results
• Behind-the-scenes content
• User testimonials

Expertise:

• Author bios with credentials
• Citations and references
• Detailed, accurate content
• Industry certifications

Authoritativeness:

• Backlinks from reputable sites
• Brand mentions
• Awards and recognition
• Guest posts on authority sites

Trustworthiness:

• HTTPS security
• Privacy policy and terms
• Contact information visible
• Customer reviews
• Transparent business practices
• About page with company info

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FINAL NOTES

This knowledge base covers universal on-site SEO principles applicable to any technology stack. When implementing:

1. Prioritize Technical Foundation: Speed, mobile, indexing
2. Create Quality Content: Match search intent, answer questions
3. Implement Structured Data: Help search engines understand
4. Monitor and Iterate: SEO is ongoing, not one-time
5. Stay Updated: Algorithm changes require adaptation

Remember: SEO is a long-term strategy. Results typically appear in 3-6 months, with full impact at 6-12 months. Focus on sustainable, white-hat practices that provide genuine value to users.