Technical SEO
Technical SEO is the work you do to make sure Google can find, crawl, understand, and index your site without obstacles. It is the foundation everything else depends on. The best content strategy, the strongest backlink profile, and the most carefully optimised pages will underperform if technical problems are blocking Google from accessing them or slowing the site down enough to harm rankings.
Unlike on-page SEO, which is mostly about what is on each page, technical SEO is mostly about the infrastructure - how pages are structured, how they load, how the site signals to Google which pages to index and which to ignore.
Why technical problems silently cost rankings
Technical issues are dangerous precisely because they are invisible to the naked eye. A page can look perfectly fine to a human visitor while simultaneously being blocked from indexing by a misconfigured robots.txt, suffering from a canonical tag pointing to the wrong URL, or loading slowly enough to trigger a significant increase in bounce rate.
According to Think with Google, 53% of mobile users abandon sites that take longer than three seconds to load. Mobile-first indexing means Google primarily uses the mobile version of your site to crawl and index - so a site that loads slowly on mobile is not just losing users, it is actively undermining its rankings.
The scale of common technical problems is also worth noting. A Reboot Online study of ecommerce websites found that 62.4% had at least one instance of broken links - a basic technical issue that harms both user experience and crawl efficiency. Technical SEO is not an advanced discipline reserved for large sites. It is a baseline that every site needs to maintain.
What this chapter covers
The five pages in this chapter address the core areas of technical SEO. They can be read in order or used as reference when diagnosing specific issues.
- Site architecture and URL structure - how to organise pages into a logical hierarchy that Google can crawl efficiently, and how URL structure signals topic relevance and site structure.
- Core Web Vitals and page speed - the three metrics Google uses to measure page experience (Largest Contentful Paint, Interaction to Next Paint, and Cumulative Layout Shift), why they are confirmed ranking factors, and how to improve them. Google's own data shows websites meeting Core Web Vitals standards see a 24% increase in user engagement.
- XML sitemaps and robots.txt - how to tell Google which pages exist and which to crawl, how to use robots.txt without accidentally blocking pages you need indexed, and how to submit sitemaps through Search Console.
- Canonicalisation - how to handle duplicate and near-duplicate content so Google indexes the right version of each page, and how canonical tags interact with indexing decisions.
- Crawl budget - how Google allocates crawl resources across your site, why crawl budget matters for larger sites, and how to ensure your most important pages are crawled frequently.