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Seo 21 June 2026 5 min read

Technical SEO Checklist: 20 Steps for Site Speed and Mobile Compatibility

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The performance of your website directly affects search engine rankings. Especially site speed and mobile compatibility are critical factors that determine user experience and conversion rates. In this article, you will find the 20 important steps you need to follow step by step when creating a technical SEO checklist, the free and paid tools you should use, and practical tips. If you’re ready, let’s start optimizing your site for speed, accessibility, and mobile-friendliness.

1. Basic Tools for Speed Analysis

The first step is to measure your current performance objectively. Google PageSpeed Insights, GTmetrix and WebPageTest are the three most preferred tools.

  • Google PageSpeed Insights: Provides separate mobile and desktop scores and offers improvement suggestions.
  • GTmetrix: Provides a detailed waterfall report and a list of recommendations.
  • WebPageTest: Performs real‑world tests with different location and device options.

2. Reduce Server Response Time (TTFB)

Time To First Byte (TTFB) is the time it takes for the server to respond to a request. Aim for a TTFB below 200 ms.

How to Improve?

  • Switch to a strong hosting provider.
  • Use server‑side caching (OPcache, Redis).
  • Remove unnecessary HTTP requests.

3. CDN (Content Delivery Network) Integration

Serving content from the nearest server based on geographic location can reduce load time by up to 30‑50%. Cloudflare, Akamai and Fastly are popular options.

4. Optimize Images

Images usually make up 60% of page weight. Reduce their size with the following steps:

  • Convert to WebP or AVIF format.
  • Add responsive srcset and sizes attributes.
  • Use lazy‑load.

5. Minify & Combine CSS and JavaScript

Reduce file size by removing whitespace, comments, and unnecessary code. Tools like uglifyjs, cssnano and webpack are ideal for this.

6. Inline Critical CSS

Add the style rules that appear above the fold directly into the HTML. This prevents render‑blocking files.

7. Defer Render‑Blocking Resources

Load JavaScript files with defer or async attributes. CSS files can be deferred with conditions such as media="print".

8. Enable HTTP/2 and HTTP/3 Protocols

These new protocols allow more efficient simultaneous transfer of multiple files. Most modern hosting providers serve HTTP/2 by default; HTTP/3 is still in beta.

9. Browser Caching (Cache‑Control) Settings

Set long‑term caching for static files (e.g., 1 year). Adding a header like Cache‑Control: public, max‑age=31536000 virtually eliminates load time on repeat visits.

10. Server Compression

GZIP or Brotli compression can shrink text‑based files (HTML, CSS, JS) by up to 70%. Add the following lines to your .htaccess file:


# GZIP Compression
AddOutputFilterByType DEFLATE text/html text/plain text/xml text/css application/javascript

11. Mobile Compatibility Test

Google’s Mobile Compatibility Test tool shows how your page looks on mobile devices and which errors are present.

12. Basics of Responsive Design

Set the viewport meta tag correctly and use percentage‑based grid systems. Flexbox and CSS Grid adapt smoothly to different screen widths.

13. Optimize Touch Targets

Ensure buttons and links are at least 48 px wide and tall. This prevents accidental taps and improves the “First Input Delay” (FID) score within Core Web Vitals.

14. Make Fonts Web‑Friendly

Add the display=swap parameter on services like Google Fonts. This shows a system font until the custom font loads, eliminating the “Flash of Unstyled Text” (FOUT) issue.

15. AMP (Accelerated Mobile Pages) Evaluation

Creating an AMP version for news, blog and e‑commerce product pages can provide a huge boost in mobile speed. However, it is not mandatory for the entire site; use it only for high‑traffic content.

16. Check 404 and Broken Links

Scan your sitemap with tools like Broken Link Checker, Screaming Frog. Broken links negatively affect user experience and SEO value.

17. XML Sitemap and Robots.txt Optimization

An XML sitemap helps search engines find your pages quickly. Remove unnecessary blocks in the robots.txt file and adjust the “Crawl‑Delay” value as needed.

18. Structured Data (Schema) Markup

Rich snippets help you stand out in mobile search results. Prefer the JSON‑LD format and validate with Google’s Structured Data Testing Tool.

19. Core Web Vitals Monitoring

Activate the “Core Web Vitals” report in Google Search Console. Regularly check LCP (Largest Contentful Paint), CLS (Cumulative Layout Shift) and FID values.

20. Continuous Monitoring and A/B Testing

Performance must be monitored even after it is improved once. Track page speed and mobile interactions in real time with monitoring solutions such as New Relic, Datadog or Google Analytics 4. Also, compare different optimization techniques with A/B tests to determine the most effective strategy.

Additional Resources You Can Use While Implementing the Technical SEO Checklist

When implementing these steps, working with a SEO agency can provide expert insight and custom reporting. Additionally, you can benefit from Web and UX Design services to create a site that is balanced in both design and performance.

Conclusion

Site speed and mobile compatibility are not only technical requirements; they are a powerful competitive advantage that directly influences the time users spend on your site and conversion rates. If you apply the 20 steps above systematically, you will have completed your technical SEO checklist thoroughly and increased your chances of ranking higher in search engine results. Remember, SEO is a dynamic process; keep your site one step ahead with regular audits and updates.

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