The Technical SEO Checklist for 2026: 30 Checks for Every Site

Technical SEO is the foundation everything else is built on. No amount of great content or link building will deliver its full potential if your site has crawlability issues, slow load times, or broken indexing signals.

This checklist covers 30 technical SEO checks across six categories. Use it for new site audits, quarterly reviews, or as a pre-launch checklist for redesigns.

1. Crawlability

1. robots.txt is correctly configured Your robots.txt file should allow search engines to crawl your important pages and block only staging environments, thin parameter URLs, and admin sections. Verify it exists, contains no errors, and doesn't accidentally block key content.

2. AI crawler access is configured For 2026, robots.txt management extends to AI crawlers. Decide which crawlers to allow for training vs search retrieval:

• OAI-SearchBot (ChatGPT Search) — allow for citation visibility
• PerplexityBot — allow for Perplexity citations
• Google-Extended — allow for Google AI Overviews
• GPTBot — your choice (training data only, doesn't affect ChatGPT Search)
• ClaudeBot — allow if you want Claude citations

3. XML sitemap exists and is submitted Your sitemap should include all canonical URLs you want indexed, with no 301 redirects, 404s, or noindex pages. Submit to Google Search Console and Bing Webmaster Tools. Reference it in robots.txt.

4. No orphaned pages Every page that should be indexed should be reachable through internal links. Orphaned pages — accessible via sitemap or direct URL but not linked from anywhere — are crawled infrequently and often excluded from the index.

5. Crawl budget is not being wasted For larger sites, check your crawl stats in Google Search Console. Signs of wasted crawl budget include: excessive parameter URLs, pagination chains with no canonical, infinite scroll without proper implementation, and session ID URLs.

2. Indexing

6. Important pages are indexable Check that key pages don't have noindex meta tags or X-Robots-Tag: noindex headers added by mistake. Use Search Console's URL Inspection tool to verify indexation status.

7. Canonical tags are correct Every page should have a self-referencing canonical tag unless it's a duplicate that should point to another URL. Check for common errors: canonicals pointing to the wrong domain, http:// canonicals on https:// pages, and paginated pages that incorrectly canonicalise to page 1.

8. No conflicting signals between canonical and noindex A page with both noindex and a canonical pointing to it creates a conflicting signal. Canonicalised pages should never have a noindex directive.

9. Hreflang is correctly implemented (international sites) If your site targets multiple languages or regions, hreflang tags must be bidirectional — every page in the hreflang cluster must reference every other page in the cluster. Missing reciprocal references are one of the most common hreflang errors.

10. Pagination is handled correctly For paginated content, each page should be independently indexable with a self-referencing canonical. The rel=next/prev pattern is deprecated — Google uses internal linking signals and breadcrumb data instead.

3. Site Architecture and URLs

11. URL structure is clean and consistent URLs should be lowercase, use hyphens (not underscores) as word separators, and not include unnecessary parameters. Avoid dynamically generated URLs like ?cat=5&p=1&sort=price for indexable content.

12. Redirect chains are minimal Each redirect adds latency and dilutes link equity. A redirect from A → B → C should be consolidated to A → C. Audit for chains longer than one hop and consolidate them.

13. No broken internal links (4xx) Internal links to 404 or 410 pages waste crawl budget and create poor user experiences. Audit internal links regularly and update or remove broken ones.

14. HTTPS is correctly implemented sitewide All pages should be served over HTTPS with no mixed content warnings. HTTP pages should 301 redirect to their HTTPS equivalent. Check the certificate is valid and not expiring imminently.

15. No duplicate content across protocols or www/non-www http://, https://, www., and non-www. versions of URLs should all resolve to a single canonical version. Verify all four combinations redirect correctly.

4. Core Web Vitals

16. LCP (Largest Contentful Paint) is under 2.5 seconds LCP measures how quickly the main content loads. For most sites, the LCP element is a hero image or heading. Optimise with preloading the LCP image, using efficient image formats (WebP, AVIF), and ensuring servers respond quickly.

17. CLS (Cumulative Layout Shift) is under 0.1 CLS measures visual stability. Common causes: images without defined dimensions, ads or embeds that load late, and fonts that swap after load. Reserve space for all dynamic elements.

18. INP (Interaction to Next Paint) is under 200ms INP replaced FID as a Core Web Vital in March 2024. It measures the responsiveness of all page interactions throughout the user's session, not just the first one. Diagnose with Chrome DevTools and PageSpeed Insights.

19. Mobile Core Web Vitals pass Check both mobile and desktop separately in Search Console's Core Web Vitals report. Mobile typically has stricter thresholds and lower performance — it's the signal Google weights more heavily for mobile-first indexing.

20. Server response time (TTFB) is under 800ms Time to First Byte measures server responsiveness. Slow TTFB affects all other timing metrics. Improve with caching, CDN deployment, and server-side optimisations.

5. Structured Data

21. Organisation schema is implemented Every site should have an Organisation (or LocalBusiness) schema on the homepage with accurate name, URL, logo, contact details, and social profiles. This is foundational for entity recognition by both Google and AI platforms.

22. Article/BlogPosting schema on blog posts Blog posts should have BlogPosting schema with datePublished, dateModified, author (Person node with name and URL), headline, and description. The dateModified field is particularly important for freshness signals in AI search.

23. FAQPage schema on FAQ sections If a page contains a FAQ section, implement FAQPage JSON-LD schema. This increases featured snippet eligibility and AI citation probability simultaneously.

24. HowTo schema on process/instructional content Step-by-step content benefits from HowTo schema, making it eligible for rich results in Google and better structured for AI extraction.

25. BreadcrumbList schema on interior pages Breadcrumb schema helps Google understand your site architecture and is displayed in search results. Ensure it's present on all non-homepage pages and matches the visible breadcrumb navigation.

6. Mobile and Performance

26. The site is fully mobile-responsive Google uses mobile-first indexing — the mobile version of your site is what's crawled and indexed. Check layout, text size, tap target size, and form usability on actual mobile devices.

27. Images are optimised and in modern formats Images should be served in WebP or AVIF format, compressed appropriately, and include width and height attributes to prevent CLS. Use lazy loading for images below the fold (loading="lazy").

28. No render-blocking resources JavaScript and CSS that blocks page rendering delays LCP. Defer non-critical JavaScript, minify CSS, and use rel=preload for critical resources.

29. llms.txt exists and is current An llms.txt file at the root of your domain (following the llmstxt.org spec) helps AI crawlers understand the scope and structure of your content. List your key pages with brief descriptions. This is increasingly treated as a technical GEO requirement.

30. Search Console shows no critical errors Check Search Console regularly for crawl errors, coverage issues, Core Web Vitals failures, and security warnings. The Coverage report and the URL Inspection tool are your primary diagnostic tools for indexing problems.

FAQs

How often should I run a technical SEO audit? A full technical audit quarterly is a reasonable cadence for most sites. Larger or more frequently updated sites benefit from monthly checks on critical metrics (indexation, crawl errors, Core Web Vitals). Set up automated alerts in Search Console for crawl errors.

What is the most common technical SEO mistake? Accidental noindex tags are one of the most common and impactful errors — particularly on staging sites that are then deployed to production without removing the noindex directive. Always check indexability on newly launched pages.

Does technical SEO affect AI citations? Yes. Crawlability, structured data, page speed, and robots.txt configuration all affect whether AI search platforms can access and correctly parse your content. Technical SEO is increasingly inseparable from GEO.

What tools are best for technical SEO audits? Screaming Frog for crawl analysis, Google Search Console for indexation and Core Web Vitals, PageSpeed Insights for performance, and Ahrefs or Semrush for backlink and redirect audits. Combine automated tools with manual URL Inspection checks for high-priority pages.

For a comprehensive technical SEO audit that covers all 30 of these checks, get in touch or start with a free audit.