The Technical SEO Checklist

Technical SEO is everything that helps search engines and AI systems crawl, understand and index your website, and this checklist covers the twenty checks that matter, in priority order. Work through it top to bottom: the early items decide whether your pages can rank at all, the later ones decide how well.

We run this exact sequence in every client audit. Most sites fail at least five of the twenty.

Checks 1 to 6: Can Search Engines Find and Keep Your Pages?

• 1. Robots.txt is not blocking what matters. One stray Disallow line can hide your whole site. Check yours at yoursite.com/robots.txt, and confirm AI crawlers are allowed too if you want AI visibility.
• 2. No accidental noindex tags. Left over from development more often than you would believe. Search Console's Pages report lists exactly what is excluded and why.
• 3. An XML sitemap that matches reality, submitted in Google Search Console, containing only live, indexable URLs.
• 4. One version of every page. HTTPS enforced, www or non-www chosen, trailing slashes consistent, canonical tags on every page. Duplicate URLs split your ranking signals.
• 5. Redirects that behave. Permanent moves use 301s, no chains longer than one hop, no redirect loops, and no internal links pointing at redirects.
• 6. Broken links fixed. 404s waste crawl budget, leak authority and erode trust. Crawl your site quarterly and repair or redirect what is broken.

Checks 7 to 11: Speed and Experience

• 7. Core Web Vitals in the green. LCP under 2.5s, INP under 200ms, CLS under 0.1, measured on real user data. Our Core Web Vitals guide explains each fix.
• 8. Images compressed and sized. Modern formats, explicit dimensions, lazy loading below the fold. The single most common speed win.
• 9. Mobile-first in fact, not theory. Google indexes the mobile version of your site. Test every template on a real phone: navigation, forms, tap targets, readability.
• 10. Render-blocking weight cut. Unused scripts, oversized CSS and third-party tags are where user experience quietly dies.
• 11. Solid hosting and caching. Slow server response times cap everything else. If TTFB is regularly over half a second, fix hosting before fine-tuning pages.

Checks 12 to 16: Structure and Understanding

• 12. Logical site architecture. Every important page within three clicks of the homepage, grouped in clear silos. Structure tells search engines what matters and how topics relate.
• 13. Internal links working for you. Descriptive anchor text, authority flowing to money pages, no orphan pages. The cheapest ranking lever most sites ignore.
• 14. Schema markup on every key template. Organisation, articles, products, FAQs, local business. Structured data helps search engines understand your content and unlocks rich results; the how-to is in our schema guide.
• 15. Clean titles and metas at scale. Unique, descriptive, no duplicates. Technically simple, endlessly neglected.
• 16. Hreflang and pagination handled, if you have international or paginated content. Small audience, big mess when wrong.

Checks 17 to 20: The AI Layer

• 17. AI crawlers welcomed. GPTBot, ClaudeBot, PerplexityBot and friends allowed in robots.txt, deliberately, not by accident either way.
• 18. An llms.txt file at your root, giving AI systems a curated map of your site. Ten minutes of work; our llms.txt guide shows the format.
• 19. Content structured for citation. Answer-first paragraphs, question headings, self-contained sections that AI search can quote cleanly.
• 20. Monitoring that catches regressions. Search Console checked monthly, crawls quarterly, and alerts on the pages that pay your invoices. Technical SEO is not a one-off project; it is upkeep, and sites that skip the upkeep donate their rankings to competitors who do not.

Technical SEO for AI Search, in More Depth

The AI layer of this technical seo checklist deserves expansion, because it is where 2026 audits differ from 2020 audits. AI systems discover the web the same way search engines always have: crawlers fetch pages, parsers extract meaning, and indexes feed the answers. That means every classic check above, crawlability, robots.txt file hygiene, clean structure, fast responses, working internal links, now pays twice: once in Google rankings and again in AI answers.

Three technical details decide most AI visibility. First, crawler access: your robots.txt file controls GPTBot, ClaudeBot, PerplexityBot and Google-Extended exactly as it controls Googlebot, and many sites block AI crawlers by accident through blanket rules. Decide your policy deliberately. Second, machine-readable meaning: schema markup and structured data help search engines and AI systems understand entities, authors, products and organisations, and pages with clear structured data are consistently easier for AI to cite accurately. Third, extractability: server-rendered content that exists in the HTML, headings that state the question, and answers that stand alone. If a crawler cannot see it without executing your JavaScript, assume some AI systems never will.

Run this AI section of the checklist quarterly, because the crawler landscape changes monthly. It takes an hour: check robots.txt against the current list of AI crawlers, confirm llms.txt is current, spot-check your key pages in an HTML-only view, and search your brand in two or three AI assistants to see what they actually say about you. Visibility in search now means visibility everywhere machines read the web, and the sites treating that as one engineering discipline are pulling ahead of those treating it as two.

Where to Start

If your site is new to all this, run checks 1 to 6 today: crawl and index problems make everything else irrelevant. Then speed, then structure, then the AI layer. And if you would rather have the whole twenty done for you with a prioritised fix list, that is precisely what our technical SEO audit delivers: book one here.

Frequently Asked Questions

What is technical SEO?

Technical SEO is the work that helps search engines find, crawl, understand and index your website: site structure, speed, mobile experience, structured data and crawl controls. It does not create demand by itself, but nothing else in your seo strategy works properly without it.

How often should I run a technical SEO audit?

A full technical seo audit once or twice a year, plus a monthly glance at Google Search Console's Pages and Core Web Vitals reports. Always audit after big changes: migrations, redesigns, or platform moves.

Do I need technical SEO for AI search too?

Yes, and it is mostly the same work. AI crawlers read the same sites Googlebot does, so crawlability, clean structure and schema markup feed AI visibility directly. The additions are AI-specific: an llms.txt file and checking that AI crawlers are not blocked in robots.txt.