Technical SEO - SEO Strategy Ltd

What is Technical SEO?

Think of your website like a house. You can have the most beautiful furniture and décor inside (that’s your content), but if the foundations are cracked, the plumbing leaks and the electrics are dodgy, nobody’s going to want to live there — and the surveyor certainly won’t give it a good report. Technical SEO is the survey. It’s everything that happens behind the scenes to make sure search engines can find, crawl, understand and rank your pages properly.

This covers a wide range of disciplines: site architecture and URL structure, crawl budget management, XML sitemaps, robots.txt configuration, canonical tags, hreflang for international sites, page speed optimisation, mobile-first indexing compliance, structured data implementation and much more. For a deep dive into the most overlooked of these disciplines, see our companion Site Architecture Guide.

Why Technical SEO Matters More Than Ever

Google’s algorithms have become increasingly sophisticated. With the rise of AI-powered search features like AI Overviews and the growing importance of E-E-A-T signals, the technical foundation of your site directly impacts whether your content gets surfaced at all. A site with poor Core Web Vitals, broken internal links or rendering issues isn’t just frustrating for users — it’s invisible to AI systems that need clean, structured data to generate citations.

We’ve seen this firsthand with clients like Pro2col, where over 1,125 duplicate URLs from HubSpot tracking parameters were diluting their authority across 146 blog posts. Once we resolved the technical debt — proper canonicalisation, parameter handling and content consolidation — their organic visibility recovered significantly within 8 weeks.

Our Approach

Every technical SEO engagement starts with a comprehensive crawl audit using industry tools combined with manual inspection. We don’t just hand you a spreadsheet of errors — we prioritise by impact, explain what each issue means in plain English, and fix the critical items directly. Our background in web development means we can implement changes ourselves rather than just making recommendations that sit in a drawer. For an honest breakdown of the tools we use and why, see our SEO Practitioner’s Toolkit.

Mobile-First Is Just Indexing Now

Google completed its universal mobile-first indexing migration in 2023. There is no “desktop index” anymore — the mobile version of your site is what Google sees, period. If content, internal links or structured data only exist on your desktop version, Google may not see them at all. This means mobile optimisation isn’t a separate discipline — it’s a fundamental technical SEO requirement.

We audit responsive design quality, touch-friendly navigation, viewport configuration, content parity between mobile and desktop, and mobile-specific opportunities like click-to-call buttons, mobile-friendly forms and location-based features. Mobile page speed is particularly critical: Google’s Core Web Vitals thresholds are the same for mobile and desktop, but mobile devices have less processing power and often slower connections. A site that passes CWV on desktop but fails on mobile is failing the only test that matters.

Crawl Budget and AI Agent Accessibility

Technical SEO has a new dimension that most agencies haven’t caught up with yet: AI agent accessibility. Search engines aren’t the only systems crawling your site anymore. AI platforms like ChatGPT (via Bing’s index), Perplexity (via its own crawler), and Google’s AI Overviews all need to access, parse and understand your content. The technical infrastructure that makes your site crawlable for Googlebot also makes it accessible to AI systems — but AI agents have additional requirements around structured data clarity, content extractability and entity disambiguation that traditional crawl optimisation doesn’t fully address.

We audit and optimise for both audiences simultaneously. Clean HTML, properly compiled schema markup, logical heading hierarchy, XML sitemaps, efficient robots.txt, canonical management and fast server response times — these fundamentals serve both search engines and AI agents. The businesses that get their technical foundation right now are building the infrastructure for visibility across every discovery platform, not just Google. That includes Bing, which serves over 10% of desktop searches and powers DuckDuckGo, Yahoo and Ecosia — see our Bing & DuckDuckGo SEO guide for the practical setup.

Frequently Asked Questions

What is the difference between technical SEO and on-page SEO?

Technical SEO deals with the infrastructure of your website — how search engines crawl, render and index your pages. Think of it as the plumbing and electrics. On-page SEO focuses on the content itself: headings, body text, images, meta tags and keyword targeting. You need both working together. The best content in the world won't rank if Google can't crawl it, and perfect technical setup won't help if the content doesn't match search intent.

How long does a technical SEO audit take?

A thorough technical audit typically takes 5-10 working days depending on the size and complexity of your site. A 50-page brochure site is straightforward. An e-commerce site with 10,000 product pages, multiple languages and a complex CMS will take longer. We always prioritise findings by business impact so you can start seeing improvements quickly, even before the full audit is complete.

Does technical SEO affect AI visibility and LLM citations?

Absolutely. Large language models like ChatGPT and Google's AI Overviews rely on structured, well-organised content to generate accurate citations. If your site has rendering issues, broken schema markup or poor crawlability, AI systems simply can't access and process your content. Technical SEO is the foundation that makes both traditional rankings and AI visibility possible.

How often should technical SEO be reviewed?

At minimum, quarterly. But realistically, technical SEO should be monitored continuously. CMS updates, new plugins, content changes and third-party scripts can introduce issues at any time. We set up automated monitoring for critical metrics like crawl errors, Core Web Vitals and indexation status so issues are caught before they impact rankings.

What is mobile-first indexing?

Mobile-first indexing means Google predominantly uses the mobile version of your website for indexing and ranking. This was rolled out universally in 2023 — there is no separate desktop index anymore. If content, links or structured data are only present on your desktop version but not mobile, Google may not see them at all. Every SEO element needs to be fully present and functional on the mobile version. We audit mobile parity as a core part of every technical engagement.

Does technical SEO affect how AI agents access my site?

Yes, increasingly so. AI platforms like ChatGPT, Perplexity and Google AI Overviews all need to crawl and parse your content. The same technical foundations that help Googlebot — clean HTML, fast load times, proper schema, logical structure — also help AI systems. But AI agents have additional requirements around content extractability and entity clarity. A site that's well-optimised technically is building the infrastructure for visibility across every discovery platform, not just traditional search.