Twenty checks. Each one takes a few minutes. If your site fails more than a handful, you have a real foundation problem that is quietly costing you visibility and enquiries. Work down the list. Tick the ones you pass, flag the ones you do not.
Key takeaways
- Run Screaming Frog monthly and export 4xx errors, redirect chains, missing titles and duplicate H1s into a fix tracker.
- Verify Core Web Vitals hit LCP under 2.5s, INP under 200ms, CLS under 0.1 for 75% of GSC mobile visits.
- Confirm Rank Math emits LocalBusiness schema with NAP, opening hours and service area on every location page.
- Check robots.txt allows CSS and JS, and that your XML sitemap includes only canonical, indexable service URLs.
- Audit the GSC Coverage report weekly and chase every ‘Discovered, currently not indexed’ URL back to a root cause.
This is the same shortlist we use to triage a new client’s site in the first week of an engagement. It is the layer underneath all the content work. Get it right and everything you write on top performs better.
Crawlability and indexing
This is the entry-level question: can Google actually find your pages? If the answer is no, nothing else matters.
| Check | Why it matters | Passing signal | Fail signal |
|---|---|---|---|
| HTTPS sitewide | Prerequisite for indexing and trust | Every URL loads over https | Mixed content warnings |
| XML sitemap | Tells Google what to crawl | Submitted in GSC, all pages listed, no errors | Missing, outdated, or contains excluded pages |
| Core Web Vitals | Speed and stability ranking factor | All three green (LCP under 2.5s) | Yellow or red on mobile |
| Schema markup | Enables rich results and AI citation | Organization, Service, FAQPage validated | No schema or errors in Rich Results Test |
| Internal linking | Signals importance and crawl paths | Every page 3 clicks or fewer from home | Orphaned pages |
1. Your site is indexed in Google. Search site:yourdomain.co.uk in Google. Your pages should appear. If none do, you are blocked from the index. Common causes: a wrongly-flipped “discourage search engines” setting, a stray robots.txt block, or a noindex tag that was left on after launch.
2. You have an XML sitemap submitted to Search Console. Check it lists all your important pages and no junk (filter pages, tag archives, admin URLs).
3. Your robots.txt does not block important pages. Visit yourdomain.co.uk/robots.txt. Look for any Disallow: lines pointing at directories you actually want indexed.
4. No important pages have a noindex tag. Spot-check half a dozen pages by viewing source and searching for “noindex”.
5. Internal links resolve. No 404s in your menus, footers or main page links. Tools like Screaming Frog or a free broken-link checker will spot these in minutes.
Site speed and Core Web Vitals
Google’s quality signals weight loading speed, particularly on mobile. AI engines too: a page that takes seven seconds to load is less likely to be cited than one that takes two. The Core Web Vitals plain-English guide covers each of these in detail.
6. Your homepage loads in under three seconds on mobile. Test in PageSpeed Insights. Anything over four seconds needs work.
7. Your Largest Contentful Paint (LCP) is under 2.5 seconds. This is the main piece of content the user sees. Slow images, oversized JavaScript and bloated themes are the usual culprits.
8. Your Cumulative Layout Shift (CLS) is under 0.1. This measures whether your page jumps about as it loads. Ads, late-loading fonts and missing image dimensions cause this. Fixes are usually quick.
9. Your Interaction to Next Paint (INP) is under 200 milliseconds. The newest Core Web Vital, measuring responsiveness. Heavy third-party scripts and badly-written JavaScript are the usual problem.
Mobile and accessibility
Over sixty percent of UK searches happen on mobile. Your mobile site is the default that Google indexes.
10. Mobile rendering is clean. Open your site on a phone. Text is readable without pinching, buttons are large enough to tap, no horizontal scrolling, no pop-ups blocking content.
11. Tap targets are at least 48 pixels. Buttons and links spaced enough that you do not fat-finger the wrong one.
12. All images have meaningful alt text. Not “image001.jpg”, not “image of laptop”. A short, descriptive sentence. This helps screen readers and AI engines understand what is on the page.
Structured data and on-page foundations
Structured data is how you tell search engines what each page is about. AI engines lean heavily on this.
13. Organisation schema on the homepage. Includes your business name, logo, address, phone, social profiles. Test in Google’s Rich Results Test.
14. Article schema on every blog post. Includes author, publish date, headline, featured image. Most SEO plugins (Rank Math, Yoast) handle this automatically when configured.
15. FAQ schema where you have FAQ blocks. Helps AI engines extract clean answers. Do not abuse this; if a question is not really a question your customers ask, do not mark it up as one.
16. Local Business schema on your contact and service pages. Especially important if you serve a specific geographic area.
17. Each page has a unique H1. One H1 per page, matching the topic. The H1 is not the same as the meta title, though they often overlap.
18. Meta titles are 50 to 60 characters. Anything longer gets truncated in search results.
19. Meta descriptions are 150 to 160 characters. Same logic, plus they should actually persuade someone to click.
Site health
20. HTTPS is on, and there are no mixed-content warnings. Browsers flag insecure resources. Mixed content (HTTPS page loading HTTP images) used to be common after a half-finished migration. Use your browser’s developer tools to spot any.
How to use this checklist
Do not try to fix everything in a week. Score the list, then sequence the fixes by impact. Crawlability and indexing first because nothing else matters if Google cannot find your pages. Then speed. Then schema. Then the smaller polish items.
For a UK service business, the realistic timeline is four to eight weeks to clean a site to a strong baseline, working with a developer or capable in-house team. Most of these items take less than an hour each.
If you want a structured run through it on your site, our SEO packages cover all twenty plus another forty checks and give you a prioritised report at the end. For trades businesses where this layer matters most, see our trades industry page.
And if you are mid-project and want a second pair of eyes on the technical foundations before launch, our freelance SEO consultant service is the right next conversation.
Frequently asked questions
How often should I run a technical SEO check?
A quick spot-check quarterly, a deep audit annually, and an extra check after any significant change to the site (redesign, plugin swap, template update, migration). Most issues creep in after changes, not from organic drift.
Do I need a developer to fix these issues?
For about half of the list, no. Title tags, meta descriptions, alt text, sitemap submission, schema via a plugin: these are content-team tasks. For Core Web Vitals, server-level performance and structural changes, you usually need a developer.
Will fixing technical SEO instantly improve my rankings?
Sometimes, often no. Technical SEO is a foundation; it removes obstacles rather than adds boosts. The lift shows up in the months that follow as your content work compounds on top of a healthy site. Without the foundation, the content work stays under-rewarded.
What is the most commonly missed item?
FAQ schema where the content is actually structured as FAQs but the schema markup never got added. It is a five-minute fix that consistently improves citation rates in AI Overviews.
How does this list relate to AI Overviews?
Every item on the list contributes. Fast, well-structured pages with clean schema get cited disproportionately by AI engines. A site that fails the technical checklist will struggle to be cited even with great content.
Where to go next
If you have run the checklist and want a clear-eyed view of where your site sits versus competitors, book a discovery call. We will walk a sample audit on your site live, no slide deck.
