The 2026 SEO Audit Checklist: The Checks We Run on Every Site

TL;DR: Our audit scores a site in seven categories and weights them: technical SEO 22%, content quality 23%, on-page SEO 20%, structured data 10%, performance 10%, AI search readiness 10% and images 5%. The overall score is the weighted average, from 0 to 100. Below is every check we run in each category and what counts as a pass. Anything that stops a page being indexed is critical regardless of category. Test a single page right now with the free Website health check, or get the whole site checked with the full report.

Most SEO audit checklists online are either 12 items long and useless, or 250 items long and also useless, because nobody can tell which of the 250 matter. This one is the list we actually run, in the order we run it, with the weights we use to turn it into a score.

What an audit checks in 2026

An SEO audit checks whether search engines and AI assistants can find a site's pages, understand them and trust them enough to show them. We split that into seven areas. Technical health covers crawling, indexing, HTTPS and redirects. Content quality asks whether a page is deep, accurate and written by someone you can name. On-page covers titles, descriptions, headings and internal links. Then come structured data, performance measured as Core Web Vitals, readiness for AI search (crawler access, text the server sends, answers that can be quoted) and images. The AI category is the one that changed most in two years and it replaced nothing, because Google states its AI features run on the same systems as regular Search, so a site with weak foundations fails in both places. A good audit ends with a prioritised list. A flat list of 80 findings with no order is how audits end up in a drawer.

How the weights work

The overall score is the weighted average. Take the made-up dental clinic from our worked example, with illustrative scores of technical 84, content 80, on-page 86, structured data 74, performance 88, AI readiness 78 and images 80. Multiply each by its weight and add them up. You get 82.08, reported as 82. Structured data at 74 is the weakest category, and it costs the total about one point because it carries only 10% of the weight. Drop the content score by ten points instead and you lose more than twice that.

Technical SEO (22%)

These decide whether the rest of the audit matters at all. A beautiful page that is not indexed scores zero in practice, however good the rest of it is.

• robots.txt returns 200, lives at the root, and does not disallow pages you want in search. Google's robots.txt introduction is the reference.
• No accidental noindex. Check the <meta name="robots"> tag and the X-Robots-Tag header on key pages. Staging settings shipped to production are the classic case.
• XML sitemap lists every indexable page and nothing else (no redirects, no 404s, no noindexed URLs), and is submitted in Search Console.
• Canonical tags point each page at itself, or at the real original when there are duplicates, following Google's canonicalization guidance.
• HTTPS everywhere, with HTTP and www/non-www variants redirecting in a single 301 hop.
• No redirect chains longer than one hop on internal links, and no internal links to 404s.
• Mobile parity. Google indexes the mobile version, so the mobile page must carry the same content, headings and structured data as desktop.
• Main content present in the raw HTML the server sends, so a crawler that skips JavaScript still reads it.
• hreflang for multilingual sites: every language version lists all versions including itself, plus x-default.
• Security headers: at least HSTS and X-Content-Type-Options, ideally a Content Security Policy.

Content quality (23%)

Content carries the most weight because once a page can rank, content is what decides whether it deserves to. The frame we use is Google's helpful content guidance and its three questions: who wrote this, how, and why.

• Each important page answers its query fully. Word count is not a ranking factor, but a 150-word service page rarely answers anything.
• Visible authorship on advice content: a byline that links to a page explaining who the author is.
• First-hand evidence: photos of your own work, real numbers, case studies, prices. This is the part competitors and AI-written pages cannot copy.
• Accurate and dated. Claims are sourced; pages that give advice show when they were last reviewed.
• No thin or duplicate pages competing with each other for the same query.
• Trust pages exist: about, contact with a real address or phone, privacy policy.

On-page SEO (20%)

• Unique title per page, leading with the topic. Google shortens titles by pixel width, so roughly 50 to 60 characters is a safe target. Google explains how it picks title links.
• Unique meta description of about 120 to 160 characters that a person would want to click.
• Exactly one H1 that names the page's topic, and headings in order (no H2 jumping to H4).
• Descriptive internal links: every page is linked from at least one other page, with anchor text that says where it goes.
• Clean URLs: readable, lowercase, hyphenated, stable.
• Open Graph tags so shared links show the right title and image.