Technical SEO Checklist for 2026

1. Crawlability & Indexation

If Google can't crawl your pages, nothing else matters.

• Robots.txt: Check yoursite.com/robots.txt. Ensure critical pages aren't disallowed.
• XML Sitemap: Should exist at /sitemap.xml. Submit to Google Search Console.
• No orphan pages: Every important page linked from at least one other page.
• Clean URLs: /blog/seo-guide not /p?id=123&cat=4. Use hyphens, not underscores.
• Canonical tags: Every page should have a self-referencing canonical.
• No duplicate content: www vs non-www, http vs https should all redirect to one version.
• Redirect chains: Keep under 3 hops. A→B→C→D loses link equity.
• Custom 404 page: Should help users navigate back, not be a dead end.

2. Site Speed & Core Web Vitals

Page experience is a ranking factor. Test at PageSpeed Insights.

• LCP under 2.5s: Largest Contentful Paint—time until main content loads.
• INP under 200ms: Interaction to Next Paint—responsiveness to user interactions.
• CLS under 0.1: Cumulative Layout Shift—page elements shouldn't jump around.
• Images optimized: WebP format, proper dimensions, lazy loading for below-fold.
• CSS/JS minified: Remove whitespace and comments from production files.
• Browser caching: Set Cache-Control headers for static assets.
• CDN configured: Cloudflare, Fastly, or AWS CloudFront for edge delivery.
• Gzip/Brotli compression: Compress text-based files. Brotli preferred.

3. Mobile Optimization

Google uses mobile-first indexing. Your mobile site IS your site in Google's eyes.

• Responsive design: One URL that adapts to screen size (not m.yoursite.com).
• Touch targets 48px minimum: Buttons and links easy to tap.
• No horizontal scrolling: Content should fit within viewport.
• Font size readable: Base font 16px minimum. No pinch-zoom needed.
• No intrusive interstitials: Full-screen popups on mobile hurt rankings.
• Viewport meta tag: Include width=device-width, initial-scale=1.

4. Security & Trust

Security is a trust signal for both users and search engines.

• HTTPS everywhere: All pages use HTTPS. HTTP 301 redirects to HTTPS.
• SSL certificate valid: Check expiration. Set up auto-renewal.
• No mixed content: All resources (images, scripts) load over HTTPS.
• Security headers: X-Content-Type-Options, X-Frame-Options, CSP.
• Privacy policy: Link from footer. Required for AdSense.
• Contact information: About page, contact page. Trust signals matter.

5. Structured Data

Schema markup enables rich results in search. Test at Rich Results Test.

• Organization schema: Homepage: name, logo, social profiles.
• Breadcrumb schema: Shows breadcrumbs in search results. Improves CTR.
• Article schema: Blog posts: headline, datePublished, author, image.
• Product schema: E-commerce: price, availability, reviews.
• FAQ schema: Expands search result with collapsible Q&A.
• No schema errors in GSC: Check Search Console → Enhancements.

6. AI Crawler Optimization (NEW)

AI search engines like ChatGPT and Perplexity now crawl the web. Being cited is the new featured snippet.

• GPTBot access: Decide: allow (be cited by ChatGPT) or block in robots.txt. Most should allow.
• ClaudeBot access: Anthropic's crawler for Claude. Same decision.
• Content structured for AI: Clear headings, bulleted lists, concise definitions.
• Clear entity relationships: Define what your brand is, what you do, who you serve.
• Authoritative voice: AI prefers citing authoritative sources. Build E-E-A-T signals.

7. Tools for Audits

Free: Google Search Console (crawl errors, indexing), PageSpeed Insights (performance), Screaming Frog (500 URLs free).
Paid: Ahrefs Site Audit, SEMrush Site Audit, Sitebulb. Worth it for comprehensive audits.