Technical SEO

Technical SEO ensures that search engines can efficiently crawl, render, and index your pages. Unlike content or link building, technical SEO issues can completely prevent a page from ranking regardless of quality — so fixing them is often the highest-leverage work.

Crawlability

Every page you want indexed must be reachable by following links from your home page. Check for orphan pages, broken links, and redirect chains in Google Search Console.

# Correct redirect — 301 passes link equity
RewriteRule ^old-page$ /new-page [R=301,L]

# Avoid: redirect chains (A → B → C) — consolidate to A → C
# Avoid: redirect loops (A → B → A)

robots.txt

User-agent: *
Disallow: /admin/
Disallow: /api/private/
Disallow: /search?          # block faceted search URLs
Allow: /api/public/         # explicitly allow subset
Crawl-delay: 1

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

XML Sitemap Best Practices

• Include only canonical, indexable URLs (no noindex, no redirects)
• Split large sitemaps into chunks of 50,000 URLs and use a sitemap index
• Update <lastmod> accurately — Google uses it to prioritise recrawling
• Submit via Google Search Console → Sitemaps

Canonical Tags

Use canonical tags to tell Google which version of a URL is authoritative when the same content is accessible at multiple URLs (pagination, query parameters, www vs non-www).

<!-- Self-referencing canonical on every page -->
<link rel="canonical" href="https://www.example.com/exact-url">

<!-- Paginated pages — canonical to page 1 is WRONG for unique content.
     Each page should self-canonical; use rel="next"/rel="prev" instead. -->
<link rel="canonical" href="https://www.example.com/blog/page/2">

Structured Data

JSON-LD structured data helps Google understand your content type and can unlock rich results (FAQ boxes, breadcrumbs, article bylines, how-to steps) in search.

{
  "@context": "https://schema.org",
  "@type": "Article",
  "headline": "Complete Guide to useEffect",
  "datePublished": "2026-01-15",
  "dateModified": "2026-04-01",
  "author": { "@type": "Person", "name": "Jane Doe" },
  "publisher": {
    "@type": "Organization",
    "name": "TechLead",
    "logo": { "@type": "ImageObject", "url": "https://example.com/logo.png" }
  }
}

Core Web Vitals Optimisation

• LCP < 2.5 s: preload the hero image (<link rel="preload" as="image">), use AVIF/WebP, serve from CDN
• INP < 200 ms: break up long tasks with setTimeout or scheduler.yield(), defer non-critical JS
• CLS < 0.1: set explicit width and height on images, reserve space for ads, avoid injecting content above existing content

Mobile-First Indexing

Google indexes and ranks the mobile version of your content. Ensure all content, structured data, and internal links present on desktop are also present on mobile.

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

HTTPS and Security Headers

Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
Content-Security-Policy: default-src 'self'; script-src 'self' 'nonce-xxx'
X-Content-Type-Options: nosniff
X-Frame-Options: DENY