Technical SEO Audit: The Checklist, and When You Need a Consultant

What a technical SEO audit actually checks

A technical SEO audit checks the foundations that let Google find, understand and serve your pages. It is the plumbing, not the decoration. If it leaks, nothing else you do (great content, a new brand, paid traffic) reaches its potential, because search engines never see the site as you intended.

Most audits cover seven areas:

1. Crawlability. Can bots reach your pages? This covers robots.txt, internal link structure, crawl budget on larger sites, and anything that blocks or wastes a crawler’s time.
2. Indexation. Of the pages Google can crawl, which has it stored and made eligible to rank? You want your important pages in and your thin, duplicate or utility pages out.
3. Site speed and Core Web Vitals. How quickly and smoothly a page loads and responds for real users on real devices.
4. Mobile usability. Google indexes the mobile version first, so if it breaks on a phone, it breaks for rankings.
5. Structured data. The schema markup that tells Google what a page is (a product, a review, an FAQ, a local business) and can earn rich results.
6. HTTPS and security. Whether the whole site loads securely, with no mixed content or certificate problems.
7. Redirects, status codes and internal linking. How URLs resolve, whether links point to live pages, and how authority flows around the site.

What a technical audit is not

It is not keyword research, content strategy or link building. It will not tell you which posts to write or which terms to target. It tells you whether the site is technically sound enough for that work to pay off. Think of it as an MOT for the machine, not a plan for where to drive it.

The technical SEO audit checklist, step by step

Work top to bottom and you will catch the issues that matter most before you get lost in the small stuff.

1. Crawl the whole site

Crawl the site the way a search engine would. A desktop crawler like the Screaming Frog SEO Spider maps every URL it can find and flags broken links, redirects, duplicate titles, missing metadata and thin pages. The free version handles up to 500 URLs; the paid licence removes the limit and adds JavaScript rendering. Sitebulb is a strong alternative if you want the findings shown visually. If your site runs on a framework like React or Vue, switch on JavaScript rendering, otherwise you audit an empty shell rather than the page a user sees.

2. Check indexation in Google Search Console

Open the Pages report in Google Search Console (formerly the Coverage report). It shows how many pages are indexed and, more usefully, why pages are not, with flags like “Crawled, currently not indexed”, “Discovered, currently not indexed” and “Duplicate without user-selected canonical”.

For any single URL, the URL Inspection tool shows how Google crawled it, which canonical it chose, and whether it rendered. If Google’s canonical is not the URL you expected, that is a signal to fix. Then compare indexed pages against the pages you actually want indexed: too few and important pages are missing, too many and you have index bloat from parameter URLs, tag archives or filtered pages.

3. Review robots.txt, XML sitemaps and canonicals

These three tell Google what to crawl and which version to trust, so a small mistake here costs you a lot.

• robots.txt: confirm nothing important is blocked. A stray Disallow: / left after a staging push is a classic way to deindex a whole site by accident. Check it references your sitemap.
• XML sitemap: list only clean, indexable, canonical URLs that return a 200 status. No redirects, 404s, noindex pages or parameter variants. Per Google Search Central, one sitemap file caps at 50,000 URLs and 50MB uncompressed, so split larger sets with a sitemap index. Submit it in Search Console.
• Canonicals: every page should self-reference a canonical unless it deliberately points elsewhere. Mixed signals (a page canonicalising elsewhere but still sitting in your sitemap, or linked as the main version) confuse Google and waste crawl budget.

4. Audit redirects and status codes

Every URL should return the status code you intend, and every link should point at a live page.

• Use 200 for live pages and 301 for anything permanently moved. Do not use a 302 (temporary) for a permanent move.
• Fix redirect chains (A redirects to B redirects to C) and loops. Each hop wastes crawl budget and leaks a little speed and authority, so point internal links straight at the final URL.
• Redirect valuable 404s (those with internal links or backlinks) to the closest live equivalent. Do not blanket-redirect everything to the homepage, because Google treats that as a soft 404.
• Watch for soft 404s: pages that say “not found” to a user but still return a 200 to Google.

5. Measure site speed and Core Web Vitals

Core Web Vitals are three metrics, and Interaction to Next Paint replaced First Input Delay in 2024, so ignore any checklist that still mentions FID. The current “good” thresholds, published by Google on web.dev, are:

• Largest Contentful Paint (LCP): under 2.5 seconds (loading).
• Interaction to Next Paint (INP): under 200 milliseconds (responsiveness).
• Cumulative Layout Shift (CLS): under 0.1 (visual stability).

Google grades these at the 75th percentile of real visits, so lab scores are a guide, not the verdict. Use PageSpeed Insights for lab and field (Chrome UX Report) data, and the Core Web Vitals report in Search Console to see which page groups fail at scale. INP is the metric most sites now trip over, usually from heavy JavaScript and third-party scripts. Common fixes: compress and correctly size images (serve WebP or AVIF), lazy-load below-the-fold media, defer non-critical JavaScript and trim third-party tags.

6. Check mobile usability

Google uses mobile-first indexing, so the mobile version is the version that counts. Google retired its standalone Mobile-Friendly Test, so check rendering in Chrome DevTools device mode and via the rendered screenshot in the URL Inspection tool. Confirm the mobile page serves the same main content and structured data as desktop, that tap targets are not crammed together, that text is readable without zooming, and that no intrusive interstitial covers the content on load.

7. Validate structured data

Structured data (schema.org markup) helps Google understand your content and can earn rich results. Run your key templates through Google’s Rich Results Test and check the enhancement reports in Search Console for errors. Prioritise the types that match your business: LocalBusiness and Organization for most companies, Product and Review for ecommerce, Article for editorial, FAQPage where it genuinely applies. Keep the markup matched to what is on the page, because a mismatch can be treated as spam.

8. Map internal links and find orphan pages

Internal links tell Google which pages matter and pass authority between them. From your crawl, look for orphan pages (indexable pages with no internal links pointing to them), important pages buried many clicks deep, and key pages with very few links in. Fix it by linking priority pages from relevant, higher-authority pages, tightening your navigation, and adding contextual links from related content. Keep the pages that matter within about three clicks of the homepage.

9. Prioritise by business impact, not tool severity

A crawler will hand you hundreds of “issues”, and most do not matter. Rank fixes by their impact on the pages that make you money, not by the colour a tool paints them. We sort findings by three questions: does it affect pages that drive revenue or leads, does it affect many pages or one, and how hard is it to fix. A canonical error across every product page beats a single missing alt tag every time.

10. Fix, then re-crawl to confirm

An audit only counts once the fixes ship and you have verified them. After changes go live, re-crawl and re-inspect the affected URLs: confirm redirects resolve in one hop, indexation flags clear, structured data validates, and Core Web Vitals improve in the field data (which updates on a rolling 28-day basis, so give it a few weeks). This close-the-loop step is the one DIY audits skip most, and it is where the value lands.

The tools: free and paid

You can run a genuine audit with free tools. Paid tools mostly buy speed, scale and better reporting.

Free and essential:

• Google Search Console for indexation, Core Web Vitals, structured data enhancements and manual actions. Non-negotiable.
• PageSpeed Insights for speed and real-world field data.
• The Rich Results Test for structured data.
• Screaming Frog SEO Spider (free up to 500 URLs) for crawling.
• Chrome DevTools for rendering and mobile checks.

Paid, for scale and depth:

• Screaming Frog full licence (around £199 a year) for unlimited crawls, JavaScript rendering and scheduling.
• Sitebulb for clearer prioritisation and client-ready reporting.
• Ahrefs or Semrush for site auditing alongside keyword and backlink data in one subscription.
• Lumar and similar for enterprise sites that need continuous monitoring.

The tools find the issues. Deciding which matter, and fixing them without breaking something else, is the human part.

How often should you run a technical SEO audit?

A full audit once or twice a year suits most sites, backed by a light monthly check and an immediate audit whenever something big changes.

• Small, stable sites (a local business or brochure site): a thorough audit once or twice a year, plus a monthly glance at the Search Console Pages and Core Web Vitals reports.
• Large or fast-changing sites (ecommerce, marketplaces, publishers): treat auditing as ongoing, because new products, filters and content create technical debt constantly.
• Always audit around a trigger: a migration, a redesign, a replatform, a domain or URL-structure change, or an unexplained drop in rankings or traffic. Those are the moments technical problems appear and go unnoticed.

When to hire a technical SEO consultant: the six signs

Do the basic audit yourself. Bring in a specialist when the problem is bigger than a checklist, tied to a major change, or costing you money you cannot trace. Six clear signs it is time:

1. A ranking or traffic drop you cannot explain. If organic traffic fell and you have ruled out seasonality and a known Google update, something technical may be behind it, and diagnosis takes experience.
2. You are planning or recovering from a migration or redesign. Replatforming or restructuring URLs is where sites lose the most organic traffic, almost always through avoidable mistakes. Get help before you launch, not after the traffic has gone.
3. The same issues keep coming back. If problems reappear after you fix them, the cause is systemic (a template, a plugin, the CMS itself), and you need someone who finds the root rather than keeps mopping the floor.
4. Your site is large or built on a complex stack. Thousands of URLs, heavy JavaScript, faceted navigation, multiple languages or a headless setup all create rendering and crawl issues that basic tools miss.
5. Search Console shows pages that will not index, or the wrong canonical. Persistent “Discovered, currently not indexed” at scale, or Google repeatedly choosing a canonical you did not intend, points to deeper signals.
6. You have a report full of issues and no idea which matter. If you cannot separate the critical from the cosmetic, or you have no developer time to action it, a consultant earns their fee on prioritisation alone.

Consultant, agency or in-house?

• A freelance consultant is often the sharpest, most cost-effective option for a defined problem or a one-off audit. You get senior expertise directly, though they usually hand fixes to your developers.
• An agency suits you when the technical work sits inside broader growth (content, local SEO, paid media, clean analytics and measurement) and you want one team owning the outcome, fixes included.
• An in-house hire makes sense once technical SEO is a permanent, full-time need, which for most UK SMEs it is not.

The most useful question to ask any of them: do you fix things, or just report them? A findings document is the start of the job, not the deliverable.

What a technical SEO consultant costs in the UK

Expect roughly £500 to £5,000 for a one-off audit, around £400 to £800 a day for specialist project work, and £1,000 to £3,000 or more a month for a retainer. These are typical 2026 ranges, not a quote, and depend on site size, build complexity and whether fixes are included.

• One-off audit: £500 to £5,000. A small site (under 100 pages) sits at the lower end, a mid-sized site in the middle, and enterprise sites higher. Be wary of anything under about £300: that is almost always a raw tool export with little human analysis, and it reads like one.
• Day rate: commonly £400 to £800, higher for senior or London-based specialists. Neutral market data puts the median SEO contractor day rate lower (ITJobsWatch recorded a UK median of £281 in the six months to August 2026), but that reflects longer contract placements rather than the specialist one-off audit and strategy days that sit at the top of the range. London tends to add 20 to 30 per cent.
• Monthly retainer: £1,000 to £3,000 or more. Ongoing technical plus wider SEO for an SME typically starts around £1,000 to £1,500 a month and rises with scope; competitive programmes run well beyond £3,000.
• Hourly: roughly £40 to £100 for freelancers, more through an agency. Useful for ad hoc advice rather than a full audit.

The biggest lever on price is whether the work includes implementing the fixes or just listing them. A cheap audit that only names problems can cost more over time than a pricier one that leaves the site measurably better.

What we find most in real audits

Across the UK sites we audit, the same handful of problems come up again and again. The examples below are composites drawn from common patterns, not any single named client.

• Index bloat. Thousands of parameter URLs, tag pages or filtered variants indexed alongside the pages that matter, spreading crawl budget thin.
• Slow LCP from images. Oversized, unoptimised hero images with no lazy-loading, still the most common cause of a failing Largest Contentful Paint.
• INP problems from scripts. Third-party tags, chat widgets and heavy JavaScript pushing interaction times over the 200-millisecond line, especially on mid-range phones.
• Redirect chains and links to dead URLs. Menus and body links pointing at URLs that 301 or 404 rather than the final destination, usually a leftover from an old redesign.
• Canonical and indexing mix-ups. Sitemaps full of non-canonical or redirected URLs, and pages sending Google contradictory signals about which version to trust.
• Broken or missing structured data. Schema that was added once, then quietly broke during a redesign and never got fixed.
• Measurement gaps. The one that surprises owners most. We regularly find analytics that cannot be trusted (conversions double-counted, key events never configured, bot traffic uncounted), which means every other decision rests on bad numbers. If your analytics are shaky, set up GA4 correctly before you optimise anything on top of it.

Our approach as a Leicester agency is simple: we fix, we do not just report. An audit is only worth what gets implemented, so we prioritise by business impact and either action the changes ourselves or brief your developers so they actually ship. That is the difference between a document and a result, and it is the core of our SEO and growth work.

Get a straight answer on your site

Not sure whether your site has a real technical problem or just needs a nudge? Book a free technical review and we will tell you what is holding your site back, which fixes matter most, and what we would do first. No jargon, no 400-line PDF, just the priorities that will actually make a difference for your business in Leicester and across the UK.