Technical SEO Audit Checklist for Large Websites

On large websites with hundreds or thousands of pages, technical issues can quietly suppress search visibility. A structured audit, run at least twice a year, keeps the foundation healthy.

Crawling and indexing

• Robots.txt allows important sections and blocks only what should be private.
• XML sitemaps list canonical, indexable URLs and update automatically.
• Important pages are no more than three or four clicks from the homepage.
• Search Console coverage reports show no unexpected exclusions.

Duplicate content and canonicals

• Every page declares a correct canonical URL.
• HTTP, HTTPS, www and non-www versions redirect to one preferred version.
• Filter and tracking parameters do not create indexable duplicates.

Site architecture

• Logical URL structure that mirrors the content hierarchy.
• Internal links connect related content and pass authority to priority pages.
• Breadcrumbs help both users and search engines understand context.

Performance

• Core Web Vitals pass for most page templates on mobile.
• Images are compressed, correctly sized and lazy-loaded.
• Third-party scripts are audited and deferred where possible.

Structured data

• Organization, breadcrumb, article, product or service schema validated without errors.
• Structured data matches visible page content.

Redirects and errors

• No redirect chains or loops.
• Broken internal links and 404 errors fixed or redirected.
• Retired pages redirect to the most relevant live page.

Internationalisation

If you serve multiple languages or regions, hreflang annotations should be complete and reciprocal.

Prioritise fixes by impact: problems on high-traffic templates first, then issues affecting many pages, then isolated errors. Re-crawl after each round of fixes to confirm results.