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Technical SEO Audit Checklist 2026: The Schema Edition for UK Websites

A technical SEO audit checklist for 2026 with a full schema markup section — covering crawlability, indexation, Core Web Vitals, structured data types, and the UK-specific technical issues most audits miss.

By NetTrackers

Technical SEO audits are not the same thing they were three years ago. The fundamentals — crawlability, indexation, page speed, canonical tags — haven't changed, but the landscape they sit in has. Schema markup that was nice-to-have in 2022 is now a serious competitive variable for rich results and AI citation. Core Web Vitals that were a vague quality signal in 2021 are now a confirmed ranking input. AI Overviews have added a new dimension to how technical content signals affect visibility.

This checklist covers the technical audit in full, with a dedicated section on structured data. It's designed for UK websites, meaning the UK-specific compliance and technical considerations are included rather than being treated as afterthoughts.

Technical SEO audit being run on UK website showing crawl data and schema markup analysis
A technical SEO audit in 2026 covers crawl architecture, Core Web Vitals, canonicalisation, and a full structured data review

Section 1: Crawlability and Indexation

These are the foundation. If Google can't crawl and index your pages, nothing else matters.

Robots.txt

  • Is robots.txt accessible at /robots.txt?
  • Are important page types (product pages, service pages, blog posts) allowed?
  • Is the sitemap URL referenced in robots.txt?
  • Are any important resources (CSS, JavaScript, image files) accidentally blocked? Blocking rendering resources prevents Google from seeing your pages as users do.

XML Sitemap

  • Is a sitemap present and submitted to Google Search Console?
  • Does the sitemap include only indexable pages (no noindex, no 404s, no canonicals pointing elsewhere)?
  • Is the sitemap under 50,000 URLs and 50MB? (If larger, split into multiple sitemaps with a sitemap index)
  • Are image and video sitemaps present for sites with significant image or video content?

Indexation Audit

  • Use site:yourdomain.co.uk to get a rough count of indexed pages. Compare to your expected total.
  • Check Search Console's Coverage report for: excluded pages, pages with crawl errors, pages indexed without submission.
  • Are any important pages showing as "Discovered — currently not indexed"? This indicates Google found but chose not to index the page — a quality signal worth investigating.
  • Identify pages that should be noindexed but aren't: thank-you pages, internal search results, staging paths if accessible.

Crawl Budget

  • For larger UK sites (1,000+ pages), review Search Console's Crawl Stats report. Are crawls increasing or decreasing?
  • Are there significant volumes of soft 404s, redirect chains, or slow-loading pages consuming crawl budget on low-value URLs?
  • Do filtered or sorted parameter URLs create URL proliferation? (/products?colour=blue&size=M creates a distinct URL from the base category page)

Section 2: Technical On-Page Signals

Title Tags

  • Every page has a unique title tag (check for duplicates in Search Console or your crawl tool)
  • Length: 50-60 characters is the conventional guide, but the real metric is pixel width — Search Console shows truncated titles
  • Primary keyword present naturally
  • UK-specific: British English spellings in title tags where applicable ("optimise" not "optimize" for UK-targeted pages)

Meta Descriptions

  • Present on all important pages (not required for every page — Google rewrites them regularly, but having them gives you control)
  • Unique across pages
  • Include a call to action relevant to UK users ("Get a free quote," "Speak to our UK team")

Heading Structure

  • Single H1 per page — descriptive of the page topic, not just the business name
  • H2s used for major sections, H3s for subsections — logical hierarchy throughout
  • H1 doesn't duplicate the title tag verbatim (though they can be similar)

Canonical Tags

  • Every page has a self-referencing canonical (present even where there's no duplicate risk — it's a clear signal to Google)
  • Paginated pages canonical correctly (page 2 should canonical to page 2, not page 1)
  • Canonicals across HTTP/HTTPS and www/non-www variations are consistent
  • Check for canonical chains: page A canonicals to page B, which canonicals to page C — these dilute the signal

Redirect Audit

  • 301 redirects used for permanent moves (not 302s, which don't pass full link equity)
  • No redirect chains longer than one hop (A → B → C should be collapsed to A → C)
  • No redirect loops
  • All moved or deleted URLs have appropriate redirects rather than 404ing

Section 3: Core Web Vitals (UK Mobile Priority)

UK mobile search accounts for over 65% of total search volume. Core Web Vitals scores on mobile are the ranking-relevant scores, not desktop.

Largest Contentful Paint (LCP) — Target: under 2.5 seconds

  • Identify the LCP element on key page types (homepage, product pages, service pages) using Lighthouse
  • Common LCP elements on UK business sites: hero images, large above-the-fold text blocks, embedded videos
  • Fixes: preload the LCP image, serve images in WebP format, ensure the LCP element isn't lazy-loaded

Cumulative Layout Shift (CLS) — Target: under 0.1

  • Common causes: images without explicit width/height attributes, dynamically injected content above existing content, web fonts that cause text reflow
  • Check Google Search Console's Core Web Vitals report for field data CLS scores — lab scores (Lighthouse) can differ from real-user experience

Interaction to Next Paint (INP) — Target: under 200ms

  • INP replaced First Input Delay (FID) as the responsiveness metric in 2024
  • Most UK business sites fail INP through JavaScript-heavy pages or slow-executing event handlers
  • Audit main thread blocking JavaScript — defer or async non-critical scripts

Time to First Byte (TTFB) — Target: under 800ms

  • TTFB is server response time. Fast CDN, server-side caching, and quality hosting produce good TTFB
  • UK sites served without CDN typically have higher TTFB than those using Cloudflare or similar

Section 4: Structured Data (Schema) Full Audit

This section gets more detailed than most technical audit checklists because schema markup has become a more significant variable — for rich results, for AI Overviews citation, and for the way Google understands and categorises your content.

Schema Types to Audit by Site Type

For UK local service businesses:

  • LocalBusiness (or a more specific subtype: Plumber, LegalService, DentistOffice, etc.)
  • Service for individual services offered
  • FAQPage for pages with question-and-answer sections
  • BreadcrumbList for site navigation
  • Review / AggregateRating if you have verified reviews on-site

For UK ecommerce:

  • Product with Offer nested — must include price, priceCurrency (GBP), availability
  • BreadcrumbList
  • Organization
  • AggregateRating if product reviews are present

For UK professional services (law, finance, accounting):

  • Organization with regulatory registration details
  • Person for individual professionals (with credentials, job title)
  • LegalService / FinancialService / AccountingService
  • FAQPage

For UK publishers and content sites:

  • Article or BlogPosting with datePublished, author, publisher
  • BreadcrumbList
  • HowTo for step-by-step instructional content

Schema Audit Steps

  1. Inventory — crawl the site and extract all structured data (Screaming Frog has a structured data report; Google Search Console's Rich Results report shows schema Google has found)

  2. Validate each type — run key page templates through Google's Rich Results Test. Note: not all schema types produce rich results (only certain types are eligible), but all schema types should be technically valid

  3. Check required vs recommended properties — Google's documentation specifies required properties for each rich result type. Missing a required property means no rich result. Check recommended properties too — they improve the quality of the rich result

  4. Look for conflicts — multiple conflicting schema implementations on the same page (old microdata alongside new JSON-LD) create confusion. JSON-LD is the recommended implementation; remove any legacy microdata or RDFa that conflicts

  5. Verify GBP-to-schema consistency — your Organisation schema should have the same name, address, phone number, and URL as your Google Business Profile. Inconsistency between the two undermines trust signals

  6. Check JSON-LD placement — JSON-LD should be in the <head> or at the end of the <body>. Placement in the middle of body content isn't invalid but is less conventional

UK-Specific Schema Considerations

  • addressCountry should be "GB" for UK addresses, not "UK"
  • Phone numbers should be in E.164 format: +447911123456 for UK mobile numbers
  • areaServed on LocalBusiness schema should list UK locations specifically — not generic "UK"
  • For regulated industries: FCA or SRA registration details can be added as identifier properties in Organization schema

Section 5: Mobile and HTTPS

Mobile-Friendliness

  • Google is mobile-first indexing for all sites — your mobile version is what Google indexes and ranks
  • Test key page templates in Google's Mobile-Friendly Test and browser DevTools device simulation
  • Check tap target sizes — interactive elements (buttons, links) need to be at least 48×48px with adequate spacing
  • Check that content isn't wider than the viewport (horizontal scrolling is a mobile usability failure)

HTTPS

  • All pages serve over HTTPS with a valid certificate
  • No mixed content (HTTP resources loading on HTTPS pages) — check browser console for mixed content warnings
  • HTTP redirects to HTTPS (not the other way around)
  • Certificate expiry monitoring — a lapsed SSL certificate instantly tanks trust signals and user experience

Section 6: International and Hreflang (Where Applicable)

For UK sites serving multiple markets:

  • Hreflang tags present on all alternate URL versions
  • Each hreflang tag includes a reciprocal tag on the target page
  • en-GB used for UK English content (not just en)
  • Hreflang included in XML sitemap as well as page-level tags

Using This Checklist

This audit checklist covers the issues that appear most often in UK website audits and that have the most measurable impact on organic performance. Not every item applies to every site — a five-page brochure site has different technical SEO needs than a 50,000-product ecommerce store.

Prioritise based on site type and the issues that are likely to be costing you the most ranking potential. For sites with significant content, the schema and indexation sections often produce the most impactful findings. For sites with performance problems, Core Web Vitals dominates.

Our SEO audits service works through this framework for UK websites, producing a prioritised remediation plan rather than just a list of findings. The distinction matters — a raw audit finding without a prioritised action plan rarely gets implemented effectively.

For the full picture on what SEO audits cover and why they matter, see what are SEO audit services and what is a technical SEO audit.

FAQ: Technical SEO Audit Checklist 2026

How often should I run a technical SEO audit for a UK website?

For actively managed sites, a partial audit (crawl, Core Web Vitals, Search Console review) monthly. A full technical audit, including schema and mobile audit, quarterly. After any significant site change — migration, platform update, major redesign — run a full audit immediately.

Is schema markup required for good Google rankings in 2026?

Not required, but increasingly impactful. Pages with properly implemented schema are more likely to appear as rich results (enhancing click-through rates), more likely to be cited in AI Overviews, and receive slightly stronger categorisation signals from Google. The ROI on schema implementation is high relative to the development cost for most UK sites.

What's the most common technical SEO issue found in UK website audits?

Thin or duplicate content on category, tag, and archive pages is the most common finding on UK sites. Canonical tag problems (particularly on ecommerce sites with faceted navigation) come second. Core Web Vitals failures on mobile — especially LCP from unoptimised images — are third.