What is technical SEO?
Technical SEO is everything that helps search engines crawl, index and understand your website, as opposed to the words on the page or the links pointing to it. It's the plumbing: if it's broken, nothing else you do will reach its potential.
Crawling and indexing
- Robots.txt exists at yoursite.com/robots.txt and isn't blocking pages you want in search results. One stray "Disallow: /" can remove a whole site from Google.
- XML sitemap lists every important page, is referenced in robots.txt and is submitted in Google Search Console. See creating a sitemap.
- No accidental noindex tags on pages that should rank, which is a common leftover from a staging site.
- Canonical tags tell search engines which version of a page is the main one, so duplicate URLs don't split your rankings. See adding canonical tags.
- No broken links. Internal links that return 404 waste crawl budget and frustrate visitors. See fixing broken links.
On-page tags
- Unique title tags on every page, ideally 50–60 characters, with the main keyword near the start. See writing title tags.
- Meta descriptions of around 140–160 characters that summarise the page and give a reason to click. Google may rewrite them, but a good one often survives. See writing meta descriptions.
- One clear H1 per page that matches what the page is about, followed by logical H2 and H3 headings.
- Descriptive image alt text that helps both accessibility and image search.
- Open Graph tags so links shared on social media and messaging apps show the right title, description and image. See adding Open Graph tags.
Site-wide signals
- HTTPS everywhere, with HTTP redirecting to HTTPS and a valid SSL certificate.
- Mobile-friendly layout. Google indexes the mobile version of your site first.
- Fast pages with good Core Web Vitals. See Core Web Vitals explained.
- Structured data (schema.org JSON-LD) describing your organisation, articles, products and FAQs. This also helps with AI search. See adding structured data.
- Clean URLs and short redirect paths, with no chains of three or four hops.
How often should I do a technical SEO audit?
Run a full audit at least once a quarter, and always after a redesign, CMS migration, new plugin or domain change. Those are the moments things break silently. Automated monitoring catches problems between audits.
What about AI search?
Technical SEO is also the foundation of GEO (generative engine optimisation). AI search tools rely on the same crawlable, well-structured pages. Once the checklist above is done, read what is GEO for the next layer.
Frequently asked questions
What is included in a technical SEO audit?
A technical SEO audit checks crawlability (robots.txt, sitemap, noindex tags), indexing (canonical tags, duplicates), on-page tags (titles, meta descriptions, headings), site speed, mobile-friendliness, HTTPS, structured data and broken links.
How long should a title tag be?
Aim for 50–60 characters. Longer titles are usually cut off in search results, so put the most important keyword and message first.
How long should a meta description be?
Around 140–160 characters. It isn't a direct ranking factor, but a clear description improves click-through rate from search results.
Do I need an XML sitemap?
Small, well-linked sites can be crawled without one, but a sitemap helps search engines discover new and updated pages faster. It's quick to add and recommended for every site.
Can I do technical SEO myself?
Yes. Most technical SEO fixes, such as titles, descriptions, sitemaps and alt text, can be done in a CMS like WordPress, Shopify or Webflow without coding. An automated audit tells you which ones your site needs.