# 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:** ```text # /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:** ```html ``` **Canonical URLs:** ```html ``` ### XML sitemap ```xml https://example.com/ 2024-01-15 daily 1.0 https://example.com/products 2024-01-14 weekly 0.8 ``` **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 ```html ``` **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 ```html ``` **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 ```html ``` **Meta description guidelines:** - 150-160 characters - Include primary keyword naturally - Compelling call-to-action - Unique for every page - Matches page content ### Heading structure ```html

Welcome to Our Store

Products

Contact Us

Blue Widgets - Premium Quality

Product Features

Durability

Design

Customer Reviews

Pricing

``` **Heading guidelines:** - Single `

` per page (the main topic) - Logical hierarchy (don't skip levels) - Include keywords naturally - Descriptive, not generic ### Image SEO ```html ``` **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 ```html Click here Read more Browse our blue widget collection Learn how to maintain your widgets ``` **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 ```html { "@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" } } ``` ### Article ```html { "@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" } ``` ### Product ```html { "@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" } } ``` ### FAQ ```html { "@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." } } ] } ``` ### Breadcrumbs ```html { "@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" } ] } ``` ### Validation Test structured data at: - [Google Rich Results Test](https://search.google.com/test/rich-results) - [Schema.org Validator](https://validator.schema.org/) --- ## Mobile SEO ### Responsive design ```html ``` ### Tap targets ```css /* ❌ Too small for mobile */ .small-link { padding: 4px; font-size: 12px; } /* ✅ Adequate tap target */ .mobile-friendly-link { padding: 12px; font-size: 16px; min-height: 48px; min-width: 48px; } ``` ### Font sizes ```css /* ❌ Too small on mobile */ body { font-size: 10px; } /* ✅ Readable without zooming */ body { font-size: 16px; line-height: 1.5; } ``` --- ## International SEO ### Hreflang tags ```html ``` ### Language declaration ```html ``` --- ## SEO audit checklist ### Critical - [ ] HTTPS enabled - [ ] robots.txt allows crawling - [ ] No `noindex` on important pages - [ ] Title tags present and unique - [ ] Single `

` per page ### High priority - [ ] Meta descriptions present - [ ] Sitemap submitted - [ ] Canonical URLs set - [ ] Mobile-responsive - [ ] Core Web Vitals passing ### Medium priority - [ ] Structured data implemented - [ ] Internal linking strategy - [ ] Image alt text - [ ] Descriptive URLs - [ ] Breadcrumb navigation ### 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 | ## References - [Google Search Central](https://developers.google.com/search) - [Schema.org](https://schema.org/) - [Core Web Vitals](../core-web-vitals/SKILL.md) - [Web Quality Audit](../web-quality-audit/SKILL.md)