The Technical SEO Audit Checklist We Actually Use

Most sites that "have an SEO problem" do not have a content problem. They have a plumbing problem: pages search engines cannot reach, duplicate URLs competing with each other, or a mobile experience so slow that visitors leave before the page settles.

This is the checklist our team works through on every audit, in the order we work through it. It is not exhaustive, but it catches the overwhelming majority of what actually moves rankings.

1. Can search engines reach your pages?

Start at the gate. If crawlers cannot get in, nothing else matters.

• robots.txt — confirm it is not blocking anything important. A Disallow: / left over from a staging environment is more common than you would hope.
• XML sitemap — present, referenced in robots.txt, and containing only canonical, indexable, 200-status URLs. A sitemap full of redirects and 404s trains crawlers to trust it less.
• Internal linking — every page you care about should be reachable within three clicks of the homepage. Orphan pages are effectively invisible.
• Crawl budget waste — check what proportion of crawl activity goes to parameterised URLs, filter combinations and pagination. On large e-commerce sites this is often the single biggest win.

2. Is the right version of each page indexed?

Duplication is the quiet killer. When five URLs serve near-identical content, search engines pick one — and it is rarely the one you wanted.

• Canonical tags present and self-referencing on primary pages.
• Faceted navigation controlled. Filter combinations should not each generate an indexable URL.
• One version of the site canonical: https, one hostname, consistent trailing slashes.
• Pagination handled sensibly, with each page distinctly titled.
• noindex applied deliberately, not accidentally inherited from a template.

Compare the number of pages in your sitemap against the number indexed. A large gap in either direction is a finding worth chasing.

3. Core Web Vitals and real-world speed

Speed is both a ranking input and a conversion input, and the second matters more.

Measure field data, not just lab scores. A perfect Lighthouse result on a fast laptop tells you very little about a customer on a mid-range Android phone on a congested network.

The interventions that reliably pay off:

• Serve modern image formats at correctly sized dimensions, with width and height attributes set.
• Defer or remove third-party scripts. Audit every tag — most sites are carrying trackers nobody remembers installing.
• Inline critical CSS, defer the rest.
• Preconnect to the origins that genuinely matter, and only those.

4. Structured data

Structured data does not directly raise rankings, but it substantially affects how your result looks, and appearance affects click-through rate.

Check that you have valid markup for the entity types that apply to you — Organization, LocalBusiness, Product, Article, FAQPage, BreadcrumbList — and that it validates without errors. Markup describing content that is not visible on the page is a policy violation, not a shortcut.

5. Mobile and accessibility

These overlap more than people expect. A page that a screen reader can navigate is usually a page a crawler can parse.

• Tap targets large enough and spaced apart.
• No horizontal scrolling at common viewport widths.
• Headings in a logical order, one h1 per page.
• Images carrying meaningful alt text — or empty alt where decorative.
• Colour contrast meeting WCAG AA.

6. The things people forget

• Redirect chains. Every hop costs equity and time. Map old URLs directly to their final destination.
• Soft 404s. Pages returning a 200 status while displaying "not found" confuse everything downstream.
• HTTPS mixed content. One insecure asset undermines the padlock.
• Hreflang, if you serve multiple regions. Get it wrong and you cannibalise yourself across markets.
• Log files. The most underused source of truth about what crawlers are actually doing on your site.

Turning a checklist into a plan

An audit that produces 200 findings and no priority order is a document nobody acts on. Sort what you find by two axes: how much traffic the affected pages represent, and how much effort the fix requires. Start where those intersect favourably.

In our experience the first four weeks of technical work — indexation cleanup and speed — produce the most visible movement, because you are removing constraints rather than trying to earn new authority. Content and link building compound on top of that foundation, but they compound slowly if the foundation is cracked.

If you would like this run against your own domain, our digital marketing team does exactly this as the first step of every engagement, and the audit itself is free.