What Is Included in a Technical SEO Audit? A Buyer's Guide

Most businesses buy an SEO audit exactly once. That makes it one of those purchases, like conveyancing or a boiler replacement, where you have no frame of reference for what good looks like until it is too late to matter.

I have reviewed a lot of audits over the years, both ones we have produced and ones clients have brought to us from elsewhere. The gap between the best and the worst is enormous, and the price does not reliably tell you which one you are getting. So here is a plain-English guide to what a technical audit should include, what it should find, and how to spot the difference.

What is a technical SEO audit?

A technical SEO audit is a structured examination of whether search engines can find, crawl, render, index and understand your website. It looks at the plumbing rather than the decoration: how your pages are discovered, how fast they load, whether the right pages are indexable and the wrong ones are not, and whether anything is quietly wasting your visibility.

It is different from a content audit (which reviews what your pages say) and a backlink audit (which reviews who links to you). A full SEO audit usually includes elements of all three, but the technical layer is the foundation. If search engines cannot reliably access and interpret your site, everything built on top underperforms.

What should a technical SEO audit include?

A thorough technical audit covers seven areas. The depth in each depends on your site, but if a proposal skips several of these entirely, ask why.

• Crawling and discovery. Can search engines reach every page that matters? This covers robots directives, XML sitemaps, internal linking, crawl traps and orphaned pages. Google's own Search Central documentation is the reference point here, and a good audit will cite it rather than invent its own rules.
• Indexation. Which pages are actually in the index, which should not be, and which are missing? Index bloat from filtered URLs and parameter pages is one of the most common problems we find on ecommerce sites.
• Rendering. Modern sites lean heavily on JavaScript, and what a crawler sees is not always what your visitor sees. An audit should compare the rendered page with the source, because content that only exists after client-side rendering can be invisible to some systems.
• Speed and Core Web Vitals. Loading performance, interactivity and layout stability, measured against the thresholds documented on web.dev. Real-user data matters more than lab scores here.
• Structured data. Whether your pages describe themselves in a machine-readable way: organisation details, products, articles, FAQs. This is increasingly important for how AI systems interpret entities, not just for rich results.
• Site architecture and internationalisation. URL structure, canonicalisation, pagination, and hreflang if you serve multiple markets. Small mistakes here multiply across thousands of URLs.
• AI retrieval readiness. The newest area, and the one most audits still ignore. More on this below.

Tooling matters less than judgement, but for transparency: like most of the industry we lean on Screaming Frog for crawling, alongside Google Search Console and real-user performance data. The crawler collects the evidence. It does not decide what matters. That is the auditor's job.

What does a good audit actually find?

A good audit finds the handful of issues that are actually costing you visibility, and says so in order of impact. Typical examples from audits we have run:

• A faceted navigation generating hundreds of thousands of crawlable URL variations, drowning the pages that earn revenue.
• Canonical tags pointing at redirected URLs, quietly telling Google to ignore key category pages.
• A staging subdomain fully indexed and competing with the live site.
• Templates where the main content renders so late that crawlers time out before seeing it.
• A migration two years earlier that left thousands of internal links passing through redirect chains.

Notice what these have in common. None of them show up as a neat score in an automated tool, and every one of them changes what you should do next. That is the test of a finding: does it change a decision? A list of 4,000 images missing alt text does not. It is a to-do item, not an insight.

How long does a technical SEO audit take?

One to three weeks for most SME sites. A small brochure site can be done thoroughly in a few days of focused work. A large ecommerce platform with international variants sits at the longer end, sometimes beyond it.

Be sceptical of both extremes. A same-day audit is a crawl export with a logo on it. An audit that takes two months on a 500-page site is being padded. The honest middle reflects the actual work: crawling, cross-referencing against Search Console and analytics data, rendering checks, and the thinking time that turns data into priorities.

How much does an SEO audit cost in the UK?

Between £500 and £7,500 as a one-off in the UK, scaling with site size and complexity. Small sites sit near the bottom of the range, large or messy ones near the top. I have covered the wider pricing picture in our UK SEO pricing guide, including why free audits are usually lead generation wearing a lab coat.

One caveat on value. An audit is worth what you do with it. A £3,000 audit that ships is a better investment than a £1,000 audit that sits in a drawer, and both beat a free one that was designed to scare you into a retainer.

How can you tell a real audit from a templated one?

Look for evidence of your site, not a generic checklist with your logo on it. The red flags are consistent:

• Every issue is "critical". Real sites have a mix of severities. If nothing is marked low priority, nothing was prioritised.
• No screenshots or URLs from your actual site. Templated audits speak in generalities because they were not written about you.
• Tool scores presented as findings. "Your site health is 62/100" is a number from a crawler, not an analysis. Google has publicly cautioned against treating third-party scores as its own ranking signals.
• No estimate of impact. A real audit says which three fixes matter most and why, in commercial terms.
• The only recommendation is a retainer. A genuine audit gives your developers enough detail to fix things without the auditor, even if you choose not to.

Does AI search change what an audit should cover?

Yes, and most audits have not caught up. The crawlers fetching your pages now include the systems behind AI Overviews, ChatGPT, Perplexity and other answer engines. They retrieve pages, split them into passages, and select what to quote. That adds a retrieval layer to auditing that did not exist a few years ago.

In my own research on what AI systems cite from long-form pages, across 480 API calls, the top third of a page earned 47% of citations despite holding 37% of the content, and bullet lists over-indexed on citations by roughly three times. Structure is not cosmetic to these systems. It decides what gets used.

Practically, that means a modern audit should also check: whether your key pages answer their core question near the top, whether content is chunked into extractable passages, whether entities (your brand, products, locations) are named explicitly rather than implied, and whether your most-cited answers exist on pages AI systems can actually fetch. We fold this into every audit as standard now, as part of our AI SEO work, because separating it from technical SEO no longer makes sense.

The honest bit

An audit fixes nothing on its own. It is a map, and a map does not move the car. I have seen genuinely good audits produce zero results because the fixes never made it through a development queue, and mediocre audits produce decent results because someone actually shipped the obvious items.

Also worth saying: not every site needs a full audit. If your site is small, recently built and visibly healthy in Search Console, a focused review of a few known problem areas can be the honest recommendation. We have told prospects exactly that, and it costs a lot less.

What happens after the audit?

The useful sequence is simple: prioritised findings, a fix plan agreed with whoever maintains your site, and a check a few weeks later that the fixes shipped and behaved as expected. That last step gets skipped surprisingly often, and it is where the value gets confirmed or lost.

If you have an audit gathering dust, or you suspect the one you paid for was a template, we are happy to give you a straight second opinion. You can see how we approach technical SEO, or just send it over and ask. Worst case, we tell you it is fine and you have lost ten minutes.