The Technical SEO Audit Checklist: 25 Checks Every UK Website Needs in 2026

Technical SEO is the foundation that everything else rests on. You can publish brilliant content and build authoritative backlinks, but if your website has technical problems, Google will struggle to crawl, index, and rank it. A technical audit is the process of finding and fixing those problems. This checklist covers the 25 technical SEO checks we run on every UK website we work with. Use it to assess your own site, or as a framework when reviewing an agency's work. ## Crawlability and Indexation **1. Check Google Search Console coverage.** How many of your pages are actually indexed? If the number is far lower than your total pages, you have an indexation problem. **2. Review your robots.txt file.** Make sure it is not accidentally blocking important pages or directories from being crawled. **3. Audit your XML sitemap.** It should include only canonical, indexable pages and be submitted to Google Search Console. **4. Identify orphan pages.** These are pages with no internal links pointing to them — Google struggles to find and rank them. **5. Check for noindex tags.** Pages you want ranking should not have a noindex directive, accidentally or otherwise. ## Site Speed and Core Web Vitals **6. Run a Lighthouse audit.** Aim for a performance score above 80 on mobile. Speed is a confirmed ranking factor. **7. Measure Largest Contentful Paint (LCP).** Your LCP should be under 2.5 seconds. If it is not, optimise your images and server response time. **8. Check Cumulative Layout Shift (CLS).** Should be under 0.1. Fix elements that shift as the page loads — usually images without dimensions or late-loading ads. **9. Measure Interaction to Next Paint (INP).** The newest Core Web Vital, replacing FID. Should be under 200 milliseconds. **10. Compress and lazy-load images.** Use modern formats like WebP and load images only when they enter the viewport. ## Mobile and User Experience **11. Test mobile-friendliness.** Google uses mobile-first indexing — your mobile experience is your ranking experience. **12. Check tap target sizes.** Buttons and links should be large enough to tap easily on a phone. **13. Review font readability on mobile.** Text below 16px is hard to read on small screens. ## On-Page and Metadata **14. Audit title tags and meta descriptions.** Every page should have a unique, keyword-relevant title under 60 characters and a compelling description under 155 characters. Use our [free SERP snippet preview tool](https://leadseo.co.uk/serp-snippet-preview-tool) to check yours. **15. Check heading structure.** One H1 per page, followed by a logical H2 and H3 hierarchy. Headings should reflect the page's topic. **16. Review canonical tags.** Each page should point to its own canonical URL to prevent duplicate content issues. **17. Check for thin content.** Pages with very little unique content will not rank. Consolidate, expand, or remove them. ## Structured Data and Schema **18. Validate your schema markup.** Use Google's Rich Results Test to check that your structured data is error-free. **19. Ensure relevant schema types.** LocalBusiness, Service, FAQ, Article, and BreadcrumbList schema all help Google understand your content. **20. Check for schema mismatches.** The content on the page should match what your schema describes. ## Security and Trust **21. Verify HTTPS is enforced.** Every page should load over HTTPS, with HTTP redirects in place. **22. Check for mixed content.** Images, scripts, and stylesheets should all use HTTPS, not HTTP. **23. Review your security headers.** Headers like Strict-Transport-Security and X-Content-Type-Options protect users and build trust. ## Links and Redirects **24. Find and fix broken links.** Both internal and external broken links waste crawl budget and harm user experience. **25. Audit redirect chains.** Redirects should go directly to the final destination, not through multiple hops. Replace 302s with 301s where the redirect is permanent. ## How to Use This Checklist Work through it methodically, but do not try to fix everything at once. Prioritise by impact: indexation and speed issues first, then on-page and schema, then the finer details. If you are running an e-commerce site or a large website, focus on crawl efficiency — Google's crawl budget is finite. Technical SEO is not a one-off task. Re-run this audit every quarter, because websites drift. New content is added, redirects accumulate, and speed degrades over time. A website that scored 90 on Lighthouse in January might score 60 by July if nobody is watching. If you would like a professional audit of your site, our [SEO agency](https://leadseo.co.uk/seo-agency) team will run the full checklist and deliver a prioritised report. Or, if you operate locally, see how we approach [SEO in London](https://leadseo.co.uk/seo-agency-london) and [Birmingham](https://leadseo.co.uk/seo-agency-birmingham). The technical foundation matters more than anything else you do in SEO. Get it right, and everything that follows is easier.