1. Crawling
Search engines can only rank what they can reach. Check that:
- robots.txt allows important sections and blocks only what genuinely shouldn't be crawled, such as admin areas, carts and internal search.
- No important pages are blocked by robots.txt, noindex tags or login walls.
- Your XML sitemap lists only canonical, indexable URLs that return 200, and it's submitted in Google Search Console and Bing Webmaster Tools.
- There are no crawl traps — infinite calendars, faceted filters or session IDs that create endless URLs.
- Your server responds quickly and reliably; frequent 5xx errors reduce how much Google crawls.
2. Indexing
- Search Console's Page indexing report shows no important pages stuck in "Crawled – currently not indexed" or "Discovered – currently not indexed".
- Every page has a self-referencing canonical tag, and duplicates point to the preferred URL.
- HTTP and HTTPS, and www and non-www, redirect to one version in a single 301 or 308 hop.
- Thin, duplicate or low-value pages are improved, consolidated or noindexed.
- Pagination and filtered pages are handled deliberately, not left to chance.
3. Rendering and JavaScript
Modern frameworks are SEO-friendly when they render on the server; problems start when key content only appears after client-side JavaScript runs.
- Important content and links are present in the initial HTML or reliably rendered — confirm with the URL Inspection tool.
- Pages built with client-side frameworks use server-side rendering or static generation for anything you want indexed.
- Internal links are real anchor elements with an href, not click handlers.
- CSS, JavaScript and images that pages depend on aren't blocked from Googlebot.
- For framework-specific details, see our technical SEO checklist for Next.js.
4. Site architecture and internal links
- Important pages are reachable within three clicks of the homepage.
- URLs are short, descriptive, lowercase and hyphenated, without unnecessary parameters.
- Deep pages have breadcrumbs, with BreadcrumbList structured data.
- Related pages link to each other with descriptive anchor text.
- There are no orphan pages, broken internal links or redirect chains.
5. Page speed and Core Web Vitals
- Largest Contentful Paint under 2.5 seconds — optimise hero images, fonts and server response time.
- Interaction to Next Paint under 200 milliseconds — cut heavy JavaScript and long main-thread tasks.
- Cumulative Layout Shift under 0.1 — set image dimensions and reserve space for embeds and banners.
- Images served in WebP or AVIF, correctly sized and lazy-loaded below the fold.
- Third-party scripts audited regularly; remove what you don't need.
6. Mobile
- A responsive layout with a correct viewport meta tag.
- The same content, links and structured data on mobile as on desktop — Google indexes the mobile version.
- Text readable and tap targets usable without zooming.
- No intrusive interstitials hiding the main content.
7. Structured data
- Organization or LocalBusiness schema with your name, logo, contact details and sameAs profile links.
- BreadcrumbList on deep pages, BlogPosting on articles and Product with offers on product pages.
- Markup validated with Google's Rich Results Test, and errors fixed in Search Console.
- Only content that's visible on the page is marked up.
8. Security and status codes
- HTTPS everywhere, with a valid certificate and no mixed content.
- Correct status codes: 200 for live pages, 301 or 308 for moved pages, 404 or 410 for removed ones.
- A helpful custom 404 page.
- No soft 404s — empty or error pages that return 200.
9. International SEO (if relevant)
- hreflang tags with correct language-region codes and reciprocal links.
- One URL per language or region, rather than content switched by IP address.
- Genuinely localised content, not just translated menus.
10. AI search readiness
AI Overviews, ChatGPT search and Perplexity draw on the same crawlable, well-structured pages — with a few extra considerations:
- Decide deliberately which AI crawlers may access your site, and set robots.txt to match.
- Write answer-first sections with specific facts, figures and tables that AI systems can quote.
- Keep business information consistent across your site and external profiles.
- Set up Bing Webmaster Tools — several AI search tools rely on Bing's index.
- Optionally publish an llms.txt file that summarises your key pages.
How often to run this checklist
Run a full technical check every quarter and after every redesign, migration or major release, and watch Search Console weekly for sudden changes in indexing, Core Web Vitals or manual actions.
If you'd rather have it done for you, our technical SEO services and SEO audits cover every item on this list — and our developers fix what we find.
Frequently asked questions
Technical SEO is the work that helps search engines crawl, render, index and understand your website: site speed, mobile-friendliness, site structure, structured data, redirects, canonicals and sitemaps.
A full audit once or twice a year, plus quick checks after every redesign, migration or major release. Monitor Google Search Console weekly in between.
Google Search Console and Bing Webmaster Tools (both free), PageSpeed Insights for Core Web Vitals, and a crawler such as Screaming Frog or Ahrefs Site Audit to find issues across the whole site.
It removes barriers, which can unlock rankings quickly when pages weren't being indexed or were too slow. To compete for valuable keywords you still need relevant content and authority.
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