Technical SEO Checklist: 20 Things Every Website Must Get Right
Technical SEO is not about tricks. It is about making sure search engines can find, understand, and trust your website. Get these 20 things right and you remove the technical barriers that hold back most sites.
Crawlability and Indexation
1. Submit an XML sitemap. Create a sitemap at yourdomain.com/sitemap.xml. Submit it in Google Search Console. This tells Google exactly what pages exist on your site. Most CMS platforms (WordPress, Next.js, Webflow) generate sitemaps automatically.
2. Configure robots.txt correctly. Place a robots.txt file at yourdomain.com/robots.txt. Use it to block pages you do not want indexed (admin pages, search results, duplicate content). Do NOT block CSS or JavaScript files — Google needs these to render your pages properly.
3. Check for noindex tags. A noindex tag tells Google not to index a page. Accidentally leaving noindex on important pages is a common mistake. Check your most important pages in Google Search Console to ensure they are indexed.
4. Fix broken links. Broken links (404 errors) waste crawl budget and create poor user experience. Use a tool like Screaming Frog or Ahrefs Site Audit to find broken links. Fix or redirect them.
5. Eliminate duplicate content. If the same content appears at multiple URLs, Google does not know which to rank. Use canonical tags to tell Google the preferred version. Common duplicate content issues: HTTP vs. HTTPS, www vs. non-www, trailing slashes, pagination.
Site Speed
6. Optimize Core Web Vitals. Google measures three key speed metrics:
- LCP (Largest Contentful Paint): How fast the main content loads. Target: under 2.5 seconds. Fix: optimize images, use a CDN, enable caching, reduce server response time.
- INP (Interaction to Next Paint): How fast the page responds to clicks. Target: under 200ms. Fix: minimize JavaScript, defer non-critical scripts, use web workers for heavy computations.
- CLS (Cumulative Layout Shift): How stable the layout is. Target: under 0.1. Fix: set dimensions for images and videos, avoid inserting content above existing content, use font-display: swap.
Test your site at PageSpeed Insights and fix all recommendations.
7. Enable caching. Browser caching stores static files (images, CSS, JavaScript) on the visitor's device. This dramatically speeds up page loads for returning visitors. Set cache-control headers for static assets.
8. Use a CDN (Content Delivery Network). A CDN (Cloudflare, Bunny CDN, AWS CloudFront) serves your static files from servers closest to each visitor. This reduces loading time for international visitors. Cloudflare's free plan is sufficient for most sites.
9. Compress images. Images are usually the largest files on a page. Compress them:
- Convert to WebP format (30-50% smaller than JPEG/PNG with same quality)
- Resize images to display dimensions (do not load a 4000px image for a 400px display)
- Use lazy loading (images load only when scrolled into view)
10. Minify CSS and JavaScript. Minification removes unnecessary characters (spaces, comments, line breaks) from code files. Most build tools and caching plugins handle this automatically.
Site Architecture
11. Create a logical URL structure. Use clean, descriptive URLs:
- Good: yourdomain.com/blog/how-to-start-freelancing
- Bad: yourdomain.com/blog/post?id=12345&cat=business
Keep URLs short, use hyphens (not underscores), and include the target keyword.
12. Build a clear navigation hierarchy. Your site structure should be:
- Home page
- Category pages
- Individual articles
Every page should be reachable within 3 clicks from the home page. Deeper pages get less crawl attention and less authority flow.
13. Use breadcrumbs. Breadcrumbs (Home > Blog > SEO > Technical SEO Guide) help users navigate and help Google understand site structure. Add breadcrumb schema markup for rich results in search.
14. Implement internal linking strategically. Internal links distribute authority throughout your site:
- Link from high-traffic pages to pages you want to boost
- Use descriptive anchor text (not "click here")
- Aim for 3-5 internal links per article
- Create topic clusters: pillar pages linking to supporting articles
Mobile Optimization
15. Ensure mobile-friendliness. Over 60% of searches happen on mobile. Google uses mobile-first indexing (it crawls the mobile version of your site). Test your site with Google's Mobile-Friendly Test. Common issues: text too small, clickable elements too close, horizontal scrolling, slow loading on mobile.
16. Use responsive design. Your site should adapt to any screen size automatically. Modern CSS frameworks (Tailwind, Bootstrap) handle this. Avoid separate mobile sites (m.yourdomain.com) — they create duplicate content issues.
Security and Trust
17. Use HTTPS. HTTPS (SSL/TLS encryption) is a confirmed Google ranking factor. Sites without HTTPS are marked as "Not Secure" in browsers, which destroys trust. Get a free SSL certificate from Let's Encrypt or your hosting provider.
18. Fix mixed content. If your site uses HTTPS but loads some resources (images, scripts) via HTTP, browsers show security warnings. Audit your site for mixed content and fix all HTTP references to HTTPS.
Structured Data
19. Add schema markup. Schema markup (structured data) helps Google understand your content. It can earn rich results (enhanced listings) in search. Common schema types:
- Article schema: For blog posts and news articles
- FAQ schema: For frequently asked questions sections
- HowTo schema: For step-by-step tutorials
- Breadcrumb schema: For navigation breadcrumbs
- Product schema: For product pages (if you sell products)
- Review schema: For product or service reviews
Use Google's Structured Data Markup Helper or a WordPress plugin (Yoast, RankMath) to generate schema markup. Test it with the Rich Results Test.
20. Set up Google Search Console. Google Search Console is a free tool that shows you how Google sees your site:
- Which pages are indexed
- What keywords drive traffic
- Crawl errors and issues
- Core Web Vitals data
- Sitemap submission
If you do only one thing on this checklist, set up Google Search Console. It is the most valuable free SEO tool available. Submit your sitemap, check for errors, and monitor your performance regularly.
The Priority Order
If you have limited time, focus on these first:
- Set up Google Search Console and submit your sitemap
- Fix Core Web Vitals (speed) issues
- Ensure mobile-friendliness
- Use HTTPS
- Fix broken links and duplicate content
- Add internal linking
These six items address the most common technical SEO problems. Once these are handled, you can focus on content quality and link building — which matter more than any individual technical detail.
Technical SEO is the foundation. Get it right, then build great content on top. Without the foundation, even the best content will struggle to rank.