Technical SEO is the foundation everything else is built on. Without it, your brilliant content and hard-won backlinks won't reach their full potential. This checklist covers the essentials every website should get right.
Crawlability & Indexing
robots.txt
Your robots.txt file tells search engines what they can and can't crawl. Common mistakes include accidentally blocking important pages or CSS/JS files that Google needs to render your pages.
- Ensure your robots.txt is accessible at
yoursite.com/robots.txt - Don't block CSS, JavaScript, or image resources
- Block admin areas, login pages, and internal search results
- Include your sitemap URL
XML Sitemap
Your sitemap is a roadmap for search engines. It should list every important page you want indexed:
- Include only canonical, indexable URLs (no duplicates, no redirects)
- Update
lastmoddates when content actually changes - Keep under 50,000 URLs per sitemap file
- Submit your sitemap in Google Search Console
Canonical Tags
Canonical tags tell Google which version of a URL is the "master" copy. This prevents duplicate content issues from URL parameters, trailing slashes, or www vs. non-www variations.
Every page should have a self-referencing canonical tag pointing to its preferred URL.
Site Speed & Core Web Vitals
Google uses Core Web Vitals as a ranking signal. The three metrics to optimize:
- LCP (Largest Contentful Paint): Target under 2.5 seconds. Optimize images, use CDN, minimize server response time
- FID / INP (Interaction to Next Paint): Target under 200ms. Reduce JavaScript execution, defer non-critical scripts
- CLS (Cumulative Layout Shift): Target under 0.1. Set image dimensions, avoid injecting content above the fold
Quick Speed Wins
- Compress images to WebP/AVIF format
- Enable gzip/Brotli compression on your server
- Lazy-load images below the fold
- Minimize CSS and JavaScript bundles
- Use a CDN for static assets
- Preconnect to required third-party origins
Mobile Optimization
Google uses mobile-first indexing, meaning it primarily uses the mobile version of your site for ranking. Ensure:
- Responsive design that adapts to all screen sizes
- Tap targets are at least 48x48 pixels with adequate spacing
- Font sizes are readable without zooming (minimum 16px body text)
- Viewport meta tag is correctly configured
- No horizontal scrolling on any page
HTTPS & Security
- All pages served over HTTPS (no mixed content warnings)
- HTTP automatically redirects to HTTPS
- SSL certificate is valid and not expiring soon
- Security headers configured (HSTS, X-Content-Type-Options)
Structured Data
Schema markup helps Google understand your content and can earn rich results (star ratings, FAQ dropdowns, breadcrumbs) in search results:
- Organization schema on homepage
- BreadcrumbList on inner pages
- Article schema on blog posts
- Product schema on product pages
- FAQ schema on FAQ pages
Validate all markup at Google's Rich Results Test before deploying.
Running Your Audit
- Start with Google Search Console — check Coverage, Experience, and Enhancements reports
- Run a crawl with a tool like Screaming Frog to find broken links, missing meta tags, and redirect chains
- Test Core Web Vitals at PageSpeed Insights for your top 10 pages
- Check mobile usability with Google's Mobile-Friendly Test
- Validate structured data with the Rich Results Test
- Fix issues by priority: crawlability first, then speed, then mobile, then structured data
Schedule this audit quarterly to catch issues before they impact your rankings.