In more detail
Technical SEO is the foundation for content and links. If key pages can't be crawled or indexed, nothing else helps them. Google's Search Essentials set out the minimum technical requirements: Googlebot isn't blocked, the page works (returns a 200 status), and it has indexable content.
Typical technical SEO areas:
- Crawlability: robots.txt, internal links, XML sitemaps and crawl budget on large sites
- Indexability: noindex directives, canonical tags, duplicate content and status codes
- Rendering: JavaScript SEO and mobile-first indexing
- Performance: Core Web Vitals and server response times
- Structure: URLs, breadcrumbs, site hierarchy and pagination
- Enhancements: structured data
- International: hreflang and regional URL structures
- Change management: redirects and migrations
Much technical SEO is invisible to visitors, which is why it's often neglected and why problems can go unnoticed for months. Technical issues also tend to arrive with change: a new CMS, a redesign, a new plugin or a hosting move can undo work that was correct last month. That's why technical SEO is better treated as ongoing monitoring than as a one-off project, with checks after every significant release.
Why it matters when hiring an agency
In our SEO Agency Landscape 2026 report, 538 of the 781 agencies in the findseo directory (68.9%) mentioned technical SEO on their own websites. A mention doesn't tell you how deep an agency's technical skills are. Ask for examples of technical problems they've diagnosed, and whether they implement fixes or write specifications for developers.
Technical work often depends on developer time, so ask what the agency will need from your team. For a quick check of any page, our Google Index Checker covers the basics: status code, robots.txt, noindex and canonical.