What Technical SEO Actually Is
Technical SEO is the branch of search optimisation concerned with making websites easy for search engine crawlers to discover, access, crawl, index, understand, and render - and with ensuring that the site's infrastructure signals quality and trustworthiness.
It's the foundation layer. Content strategy and link building sit on top of it. Without solid technical foundations, both are less effective.
Crawlability: Can Google Get In?
Before Google can rank your content, it has to be able to crawl and index it. A surprising number of sites have inadvertent barriers: pages blocked by 'robots.txt', important content rendered only by JavaScript (invisible to basic crawlers), broken internal links, and crawl budget issues on large sites.
Robots.txt should block only content that genuinely shouldn't be indexed - admin pages, thank-you pages, duplicate content. Do not block CSS and JavaScript files - Google needs to render pages.
XML Sitemap tells Google where to find your important pages. It should include all canonical URLs, exclude paginated duplicates and parameters, and be submitted in Search Console.
Internal link structure is the road map that lets Google's crawlers navigate your site. Pages that are not linked from any other page (orphan pages) may never be crawled.
Indexability: Is the Right Content in the Index?
A page being crawled doesn't guarantee it's indexed. Indexing requires the page to pass Google's quality threshold: sufficient content, no duplicate of a canonical elsewhere, no noindex directive, and a confirmed canonical tag.
Canonical tags ('<link rel="canonical">') are critical for sites with duplicate or near-duplicate content. Product pages with URL parameters, paginated listings, and AMP versions all need canonical signals to avoid index dilution.
The noindex tag ('<meta name="robots" content="noindex">') should only be applied deliberately - to thank-you pages, login pages, and internal search results.
Site Architecture: The Hierarchy of Crawl Priority
Pages closer to the homepage (fewer clicks away) receive more crawl attention and pass more link equity. A key metric: no important page should be more than 3 clicks from the homepage.
Flat site architecture - where category pages sit directly under the root and content pages sit directly under categories - is more crawlable and distributes link equity more efficiently than deep, nested structures.
HTTPS and Security Signals
HTTPS is a confirmed (if lightweight) ranking factor. More importantly, a non-HTTPS site displays browser security warnings that destroy user trust. Every site should be on HTTPS with a valid SSL certificate, with HTTP redirecting to HTTPS.
Redirect chains - where a page redirects to another redirect before reaching the destination - dilute PageRank and slow crawling. Audit and collapse redirect chains to single 301 redirects.
Structured Data: Speaking Google's Language
Schema markup is the formal way to tell Google what type of content is on a page: Article, Product, Event, Recipe, LocalBusiness, FAQ. Structured data enables rich results and helps Google's knowledge graph correctly categorise your site.
Use Google's Rich Results Test tool to validate schema implementations.
Core Web Vitals: Technical UX
LCP, CLS, and INP (see our full Core Web Vitals post) are both UX metrics and ranking signals. Technical SEO and UX optimisation are the same discipline when it comes to page experience.
Regular Technical Audits
Technical SEO isn't a one-time task. Sites accumulate technical debt: broken links, crawl errors, redirect issues, and performance regressions. Monthly monitoring via Search Console and quarterly deep audits via tools like Screaming Frog or Ahrefs Site Audit are the minimum maintenance programme.
