Technical SEO
Technical SEO refers to the optimisation of a website’s technical infrastructure to improve its ability to be crawled, indexed, and ranked by search engines. While content SEO focuses on what your pages say, and off-page SEO focuses on who links to them, technical SEO focuses on whether search engines can find, read, and process your pages at all.
Example
A site publishes 100 well-researched articles on high-value keywords. However, the site uses JavaScript-heavy rendering that Googlebot struggles to process, has 40 redirect chains from old URL rewrites, and serves pages in 8 seconds. The articles will not rank — not because the content is bad, but because the technical foundation is broken. Technical SEO fixes the foundation.
Core Technical SEO Disciplines
Crawlability. Can Googlebot find and access your pages? Key issues: broken links, robots.txt misconfigurations, pages blocked by noindex that should be indexable, and crawl budget waste from duplicate URLs.
Indexability. Once crawled, is Google adding your pages to its index? Issues: noindex directives, canonical tag conflicts, thin content penalties, and pages returning 4xx or 5xx HTTP status codes.
Site speed. Google uses Core Web Vitals as a ranking signal. The three metrics:
- LCP (Largest Contentful Paint): should be under 2.5 seconds
- INP (Interaction to Next Paint): should be under 200ms
- CLS (Cumulative Layout Shift): should be under 0.1
Structured data (schema markup). Adding schema.org markup to your pages enables Google to display rich results in the SERP — review stars, FAQ accordions, recipe cards, product prices. Every review and comparison page on this site uses schema markup.
URL structure. Clean, descriptive URLs (yourdomain.com/seo-tools-comparison/ rather than yourdomain.com/?p=1247) are easier for Googlebot to understand and for users to share.
HTTPS. All pages should be served over HTTPS. HTTP pages receive a ranking penalty in 2026.
Mobile-first indexing. Google indexes the mobile version of your site. Your mobile experience must be equivalent to your desktop experience in content and structure.
What Technical SEO Is Not
Technical SEO does not directly create rankings. It removes the barriers that prevent good content and strong links from ranking. Think of it as the foundation: without it, everything built above is unstable. With it in place, content and links can do their job.
Tools for Technical SEO Audits
- Screaming Frog at £149/yr — the industry standard for technical audits. Crawls your site locally, like Googlebot, with no intermediary. The best tool for deep technical work.
- Semrush Pro at $139.95/mo — Site Audit covers 100,000 URLs, surfaces Core Web Vitals data, and prioritises issues by impact. Good for ongoing monitoring.
- Ahrefs Lite at $129/mo — Site Audit at Lite tier (50,000 URLs). Solid for content and link issues alongside technical coverage.
- Google Search Console (free) — the direct source of truth for what Google actually sees. Crawl errors, coverage issues, and Core Web Vitals data are available at no cost.
How to Prioritise Technical SEO Issues
When a site audit surfaces 200+ issues (common on older sites), prioritise by impact:
- Crawl blocks (pages blocked from Googlebot that should be indexed) — highest priority
- Broken internal links (4xx errors on pages that are linked to internally) — high priority
- Redirect chains (3+ hops in a redirect chain) — high priority
- Duplicate content (pages with identical title tags, H1s, or content) — medium priority
- Core Web Vitals failures — medium priority; fix LCP issues first
- Missing schema markup — lower priority; adds rich results but does not directly affect rankings