Technical SEO Audit Checklist for High-Performing Websites

Technical SEO is the behind-the-scenes foundation that helps search engines crawl, index, and understand your content. A well-executed technical audit ensures your website is fast, accessible, and primed for ranking opportunities. This comprehensive checklist will help you run a structured audit, prioritise fixes, and improve your site's organic performance.

1. Benchmark Current Performance

Before making any changes, document the current state of your website so you can measure improvements.

• Organic traffic and impressions: Export data from Google Search Console for the last 3–6 months.
• Top landing pages and queries: Identify the pages that bring the most traffic and the queries they rank for.
• Technical health overview: Run baseline crawls with tools like Screaming Frog, Sitebulb, or Ahrefs Site Audit.
• Core Web Vitals: Capture PageSpeed Insights reports for priority URLs to track performance shifts.

2. Crawl Your Website

A site crawl reveals how search engines discover your pages and where technical issues exist.

Recommended Crawl Settings

• User agent: Use both desktop and mobile user agents to surface device-specific issues.
• Crawl depth: Ensure the crawl reaches at least five levels deep to uncover buried content.
• Render JavaScript: Enable JavaScript rendering for single-page applications or dynamic content.
• Respect robots.txt: Review disallowed paths to confirm critical sections are not blocked.

Key Metrics to Capture

• Indexable vs non-indexable URLs
• HTTP status codes (2xx, 3xx, 4xx, 5xx)
• Page titles, meta descriptions, and headers
• Word count and thin content warnings
• Duplicate content signals

3. Ensure Crawlability and Indexation

Search engines must be able to access and index your most valuable content. Fix these issues first.

Robots.txt Review

• Confirm that essential directories (e.g. /services/, /blog/) are crawlable.
• Allow CSS and JavaScript files so Google can render your pages accurately.
• Block internal search results, staging environments, and admin areas.

XML Sitemaps

• Create segmented sitemaps (blog, services, products) for easier management.
• Ensure sitemap URLs return 200 status codes and are listed in robots.txt.
• Submit updated sitemaps in Google Search Console and Bing Webmaster Tools.

Indexation Checks

• Use the site: operator and Google Search Console's Coverage report to find excluded URLs.
• Resolve issues like Crawled – currently not indexed, Duplicate without user-selected canonical, and Soft 404s.
• For large sites, prioritise templates or sections with systematic errors.

4. Fix Status Code Issues

A clean status code profile supports positive user experience and crawl efficiency.

4xx Errors

• Redirect broken inbound links to the most relevant live page.
• Fix internal links that point to 404 pages, especially from navigation or high-traffic content.
• Create a custom 404 page that guides users back to useful resources.

3xx Redirects

• Remove redirect chains and loops that waste crawl budget and slow page loads.
• Update internal links to point directly to the final destination.
• Ensure legacy redirects (e.g. HTTP > HTTPS, old domain > new domain) remain active.

5xx Server Errors

• Investigate server logs for spikes and error patterns.
• Work with your hosting provider or dev team to stabilise infrastructure.
• Implement uptime monitoring alerts to catch issues proactively.

5. Optimise Site Architecture

A logical site structure helps both users and search engines understand your content hierarchy.

• Maintain a shallow architecture where important pages are accessible within three clicks.
• Group related content into topical hubs and use internal linking to connect subtopics.
• Add breadcrumb navigation to improve contextual signals and click-through rates in SERPs.
• Audit pagination to ensure it uses proper rel="next"/"prev" or modern alternatives like Load More buttons with correct linking.

6. Improve Page Speed and Core Web Vitals

Google uses real-world performance data as a ranking factor. Prioritise fixes that improve user experience and Core Web Vitals (CWV).

Largest Contentful Paint (LCP)

• Serve hero images in next-gen formats (WebP/AVIF) and lazy-load below-the-fold assets.
• Use critical CSS to render above-the-fold content quickly.
• Implement server-side rendering or static site generation where possible.

First Input Delay (FID) / Interaction to Next Paint (INP)

• Minimise main-thread blocking JavaScript and defer non-critical scripts.
• Break long tasks into smaller chunks using requestIdleCallback or Web Workers.
• Audit third-party scripts and remove unused tracking pixels.

Cumulative Layout Shift (CLS)

• Always define width and height attributes for images and embeds.
• Reserve space for ads, banners, and other dynamic elements.
• Use CSS aspect-ratio boxes for responsive media.

7. Strengthen Mobile Experience

With Google's mobile-first indexing, your mobile experience is what determines rankings.

• Test key templates with Google's Mobile-Friendly Test and Lighthouse audits.
• Ensure tap targets meet minimum size guidelines (48x48 CSS pixels).
• Avoid intrusive interstitials that block content on mobile devices.
• Check viewport settings to prevent horizontal scrolling or zoom issues.

8. Enhance Security and Accessibility

Secure, accessible sites build trust and serve a wider audience.

• Confirm your SSL certificate is valid and automatically renewed.
• Force HTTPS across all pages, including canonical tags and internal links.
• Implement HTTP Strict Transport Security (HSTS) for additional protection.
• Use automated accessibility scanners (axe, WAVE) to identify WCAG compliance gaps.

9. Structured Data and SERP Enhancements

Structured data helps search engines understand your content and can unlock rich results.

• Add schema markup for organisation, breadcrumbs, products, FAQs, and articles.
• Test implementation with Google's Rich Results Test and monitor enhancements in Search Console.
• Ensure structured data matches on-page content to avoid manual actions.

10. Log File Analysis

Server log files reveal how search bots actually crawl your site.

• Identify the most frequently crawled URLs and compare with your priority pages.
• Spot wasteful crawling on parameter URLs or outdated content.
• Monitor crawl frequency after major site changes or migrations.

11. International and Local Considerations

If you target multiple regions or languages, ensure your site signals the right audience.

• Implement hreflang tags that correctly map language and regional variations.
• Maintain country-specific sitemaps for localised content.
• For local businesses, align on-site NAP details with Google Business Profile data.

12. Prioritise and Implement Fixes

Not every issue has equal impact. Prioritise based on effort vs potential gain.

1. Critical Issues (Fix Immediately): Security problems, non-indexed priority pages, widespread 404s.
2. High Impact (Fix Next): Slow Core Web Vitals, duplicate content templates, structured data opportunities.
3. Medium Impact (Plan): Minor metadata issues, orphan pages, low-priority redirects.
4. Low Impact (Monitor): Cosmetic adjustments, low-volume pages, seasonal content updates.

Create a roadmap with owners, deadlines, and KPIs for each task. Track progress in project management tools such as Asana, ClickUp, or Monday.com.

13. Report and Iterate

Technical SEO is not a one-time exercise. Set up ongoing monitoring to stay ahead of issues.

• Schedule monthly crawls to surface new problems and verify previous fixes.
• Review Search Console Coverage and Page Experience reports weekly.
• Monitor ranking improvements for high-priority keywords after technical changes.
• Document learnings and refine your audit checklist for future sprints.

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By completing this technical SEO audit checklist, you create a fast, crawlable, and search-friendly website that supports sustainable growth. Pair these technical enhancements with strategic content and digital PR to unlock your full organic potential.