Technical SEO Audit Checklist: 40 Checks for Google and AI Search

A technical SEO audit checks whether search engines and AI systems can find, crawl, render, index and understand your website. It is the foundation under everything else: the best content in your market won’t rank in Google, or be cited in an AI answer, if crawlers can’t reach it or the page sends mixed signals about what it is. This checklist covers the 40 checks we run first on every site, grouped into ten areas, with the free tool to use for each and what “pass” looks like. It is written for business owners and marketers, so each check says why it matters, not just what to click.

Tools you need

• Google Search Console (free): indexing, Core Web Vitals, URL Inspection, sitemaps, manual actions.
• PageSpeed Insights (free): real-user Core Web Vitals and lab diagnostics for one URL at a time.
• Rich Results Test and the Schema Markup Validator (free): structured data errors and eligibility.
• A crawler such as Screaming Frog SEO Spider (free up to 500 URLs) or Semrush Site Audit: status codes, titles, canonicals, internal links and redirect chains across the whole site.
• Bing Webmaster Tools (free): Bing’s index also feeds several AI assistants, so check it too.

1. Crawlability

1. robots.txt loads at yourdomain.com/robots.txt and returns a 200 or a 404, not a 5xx error. Persistent server errors on robots.txt can make Google stop crawling the site.
2. Nothing important is disallowed. Check that service pages, blog posts, CSS and JavaScript aren’t blocked. Test key URLs with Search Console’s URL Inspection.
3. AI search crawlers are allowed if you want to be cited. Look for OAI-SearchBot (ChatGPT search), PerplexityBot and Claude-SearchBot. Training crawlers such as GPTBot and ClaudeBot are a separate choice. Blocking Google-Extended doesn’t affect Google Search or AI Overviews. You don’t need an llms.txt file for any of this.
4. Your firewall and CDN don’t block them either. Bot protection from Cloudflare, security plugins and hosts often returns 403 errors to crawlers that robots.txt allows. Check server logs or your CDN’s bot report.
5. Server response is fast and stable. Search Console’s Crawl stats report shows host problems and average response time.

2. Indexing

6. Important pages are indexed. Review Search Console’s Page indexing report and the reasons pages aren’t indexed.
7. No accidental noindex. Crawl the site and filter for noindex in the meta robots tag or X-Robots-Tag header. A leftover “Discourage search engines” setting on WordPress is a classic.
8. Thin and utility pages are excluded on purpose: thank-you pages, internal search results, tag archives with one post, staging copies.
9. “Crawled, currently not indexed” is reviewed. Many URLs here usually signal thin, duplicate or low-value content rather than a technical fault.
10. The site: search looks right. Search site:yourdomain.com and look for old pages, test pages or another domain’s copies.

3. XML sitemap

11. A sitemap exists and is submitted in Search Console and Bing Webmaster Tools, and listed in robots.txt.
12. It contains only canonical, indexable URLs that return 200. No redirects, 404s or noindexed pages.
13. lastmod dates are accurate. Google uses lastmod when it is consistently correct and ignores priority and changefreq.
14. It updates automatically when you publish or delete a page. If you use a caching plugin, purge the cached sitemap after big changes.

4. Site architecture and internal links

15. Key pages are within three clicks of the homepage.
16. No orphan pages. Every page you want indexed has at least one internal link from a crawlable page.
17. Links are real HTML links (<a href>), not buttons or scripts that only work on click.
18. Anchor text describes the target, for example “technical SEO services” rather than “learn more”.
19. URLs are clean and stable: readable words, lowercase, hyphens, no session IDs.

5. Duplicates, canonicals and redirects

20. One version of the site resolves. http, https, www and non-www all redirect to a single version in one hop.
21. Every indexable page has a self-referencing canonical, and duplicates point to the preferred URL.
22. No redirect chains or loops. Update internal links to point straight at the final URL.
23. Broken links are fixed. Internal links to 404s waste crawling and frustrate users. Redirect removed pages that had links or traffic to their closest replacement.
24. Soft 404s are resolved. “Not found” pages must return a real 404 status code.

6. Rendering and JavaScript

25. Google sees your content. Use URL Inspection, then “View crawled page”, and confirm the main text, links and structured data are in the rendered HTML.
26. Critical content isn’t hidden behind interactions such as tabs that load on click or infinite scroll without paginated URLs.
27. Important facts aren’t only in images or PDFs. Prices, services, locations and key answers should be in HTML text that every crawler can read.

7. On-page elements

28. Each page has a unique, descriptive title that leads with what the page is about.
29. Each page has a unique meta description that matches the page. It doesn’t affect ranking, but it shapes clicks and what Google may show.
30. One clear H1 per page and a logical H2 and H3 structure.
31. Images have descriptive alt text and sensible file sizes.
32. Snippet controls are deliberate. nosnippet, max-snippet and data-nosnippet limit what Google can show in results and in AI Overviews and AI Mode. Use them only where you mean to.

8. Page experience and Core Web Vitals

33. Core Web Vitals pass for real users: Largest Contentful Paint at or under 2.5 seconds, Interaction to Next Paint at or under 200 milliseconds, and Cumulative Layout Shift at or under 0.1, measured at the 75th percentile.
34. Mobile works fully. Google indexes the mobile version, so content, links and structured data must be present on mobile, not only on desktop.
35. HTTPS everywhere, with no mixed-content warnings.
36. No intrusive interstitials that block the main content on arrival.

9. Structured data

37. Markup validates in the Rich Results Test, with no critical errors.
38. It matches what is visible on the page. Markup describing content users can’t see breaks Google’s guidelines.
39. The basics are in place: Organization (or LocalBusiness) on the homepage, BreadcrumbList, and Article on blog posts with a real author. Google doesn’t require special markup for AI features, but accurate schema removes ambiguity about who you are.

10. Entity and local signals

40. Your business facts are identical everywhere: name, address, phone, services and hours match across your site, Google Business Profile, Bing Places and key directories. AI assistants describe businesses by combining these sources, and conflicting facts make them hedge.

Prioritizing what you find

How often to run a technical SEO audit

Run a full audit once a year and after any redesign, migration, platform change or domain move. Check Search Console’s indexing and Core Web Vitals reports monthly, and keep an eye on its email alerts. Most technical problems we find were introduced by a plugin update, a theme change or a security setting, not by the original build.

Technical SEO and AI visibility

Google’s AI Overviews and AI Mode draw on pages from Google’s normal index, so a page needs to be indexed and eligible for a snippet to be used. Independent assistants such as ChatGPT, Perplexity and Claude run their own crawlers and search, which is why crawler access and HTML-readable facts matter so much. A technical audit doesn’t make you the recommended business, but it removes the reasons an engine couldn’t recommend you. Our guide to showing up in Google AI Overviews covers the next layer.

Want it done for you?

Foundier’s AI Visibility Audit includes a technical SEO review covering crawlability, indexing, site structure, Core Web Vitals and schema, plus testing of 25 buyer questions across ChatGPT, Google AI Overviews, Perplexity and Claude, delivered as a ranked fix plan in five business days for $750. If you already know the technical layer is the problem, our technical SEO services fix it end to end.

FAQ

What is a technical SEO audit?

A technical SEO audit checks whether search engines can crawl, render, index and understand your website. It covers robots.txt, sitemaps, indexing, canonicals, redirects, site speed, mobile usability, structured data and internal links.

What should a technical SEO audit checklist include?

At minimum: crawl access, indexing status, XML sitemap, site architecture and internal links, duplicates and canonicals, redirects and broken links, JavaScript rendering, titles and headings, Core Web Vitals, mobile, HTTPS and structured data.

How long does a technical SEO audit take?

For a small business site of under 200 pages, a thorough audit takes a few days. Large or JavaScript-heavy sites take longer, mainly because of crawling and rendering checks.

Can I do a technical SEO audit for free?

Yes. Google Search Console, PageSpeed Insights, the Rich Results Test, Bing Webmaster Tools and the free version of Screaming Frog cover most checks for a small site. Paid tools mainly save time on larger sites.

Does technical SEO affect AI search?

Yes. Google’s AI features use pages from its search index, and other AI assistants rely on their own crawlers. If a page is blocked, not indexed or hides its key facts in scripts or images, AI systems are less likely to use it.