A Technical SEO Audit is the backbone of every successful SEO strategy. Even if your content is strong and your keywords are well-optimized, your website can still fail to rank if search engines cannot properly crawl, interpret, or index your pages.

A technical SEO audit helps you uncover hidden issues related to speed, crawlability, indexing, architecture, mobile experience, structured data, and security. To make the process easier, here is a Top 20-step technical SEO checklist you can use to evaluate your website from top to bottom.

1. Check Website Accessibility & Crawlability

Before anything else, make sure search engines can access your website.

Review these:

1. robots.txt file for accidental blocking
2. Ensure important pages are not disallowed
3. No noindex tags on key pages
4. Limit crawl traps like infinite filters or session IDs

If search engines cannot crawl your site, nothing else matters.

2. Verify Index Status in Search Console

Use Google Search Console to check:

1. Indexed pages
2. Excluded pages
3. Discovered but not indexed
4. Crawled but not indexed

These reveal how search engines interpret your site.

3. Fix Page Speed Issues (Core Web Vitals)

Page speed is a ranking factor and a major user experience signal.

Audit and improve:

1. Largest Contentful Paint (LCP)
2. Interaction to Next Paint (INP)
3. Cumulative Layout Shift (CLS)
4. TTFB (Time to First Byte)
5. Excessive scripts and large images

A faster site boosts rankings and engagement.

4. Ensure Mobile Optimization

Google uses mobile-first indexing.

Review:

1. Responsive design
2. Touch-friendly buttons
3. Readable text
4. Proper layout on small screens
5. No intrusive popups

Poor mobile UX = ranking drops.

5. Review XML Sitemap & Submit Updated Version

Your sitemap should include only:

1. Canonical versions of pages
2. Important URLs
3. Fresh and updated pages

Remove:

1. Tag pages
2. Filter pages
3. Duplicate URLs

Submit it in Google Search Console.

6. Optimize Site Architecture

Your website structure should be:

1. Clean
2. Organized
3. Easy to navigate
4. Three-clicks deep (max)

A good structure improves user experience and crawl depth.

7. Audit Internal Linking Strategy

Internal links help distribute authority, improve crawling, and connect related content.

Checklist:

1. Link top pages from homepage
2. Use descriptive anchor text
3. Fix broken internal links
4. Avoid orphan pages (pages with no internal links)
5. Add contextual links for depth

8. Check for Redirect Issues

Redirects are essential but can become problematic.

Fix:

1. Redirect chains (A → B → C → D)
2. Redirect loops
3. Outdated 301/302 usage
4. Mass redirects from old migrations

Redirect issues slow crawling and waste crawl budget.

9. Fix Broken Links (Internal & External)

Broken links create a bad user experience and block crawlers.

You should:

1. Fix 404s
2. Remove outdated links
3. Replace broken external resources

Ensure all links point to live, relevant pages.

10. Audit HTTPS & Security Issues

Security is a ranking signal.

Check:

1. All pages served over HTTPS
2. No mixed-content errors (HTTP resources on HTTPS pages)
3. Valid SSL certificate
4. Secure cookies

Google penalizes unsecure sites.

11. Implement Canonical Tags Correctly

Canonicalization prevents duplicate content issues.

Make sure:

1. Each page has a self-referencing canonical
2. Variations (UTM, filters, parameters) point to the main URL
3. No conflicting canonicals across pages

Improper canonicals confuse search engines.

12. Analyze URL Parameters & Filter Pages

Parameter-based URLs often create thousands of duplicates, hurting crawl budget.

Fix:

1. Block unimportant parameters in robots.txt
2. Add canonical to main page
3. Use Google Search Console parameter settings
4. Convert important filters into static URLs

This avoids crawl waste.

13. Check for Duplicate Content Across Pages

Duplicate content harms ranking and confuses search engines.

Audit:

1. Duplicate meta tags
2. Similar product descriptions
3. Thin pages targeting same keywords
4. HTTP vs HTTPS duplicates
5. Printer-friendly versions

Fix with canonical tags, redirects, or content rewrites.

14. Evaluate Structured Data (Schema Markup)

Structured data enhances search visibility through rich snippets.

Common schemas:

1. FAQ
2. Article
3. Breadcrumb
4. Local business
5. Product
6. Review

Ensure your schema:

1. Is valid
2. Matches actual page content
3. Uses JSON-LD format

Valid schema boosts CTR without adding content.

15. Analyze Content Depth & Relevance

Technical SEO supports content — it doesn’t replace it.

Check if content:

1. Matches search intent
2. Covers topics comprehensively
3. Avoids thin pages
4. Offers value beyond competitors

Quality content remains essential.

16. Audit Pagination & Infinite Scrolling

Large sites need proper pagination rules.

Checklist:

1. Avoid infinite scrolling without crawlable paginated URLs
2. Provide links to page 2, 3, 4, etc.
3. Use rel="prev" and rel="next" (though deprecated, still useful for structure)

Bad pagination = crawl budget drain.

17. Fix Server Errors (5xx Issues)

Server errors stop crawling immediately.

Check for:

1. 500 (Server error)
2. 503 (Service unavailable)
3. 504 (Gateway timeout)

These errors reduce crawl rate and harm rankings.

18. Review Hreflang Implementation (For Multi-Language Sites)

Incorrect hreflang tags cause duplicate content across regions.

Check:

1. ISO language and region codes
2. Correct return tags
3. Correct x-default usage
4. No conflicting canonicals

Poor hreflang = poor international SEO.

19. Validate JavaScript Rendering

Search engines MAY struggle with JavaScript-heavy sites.

Checklist:

1. Test in Google Search Console
2. Ensure important content renders quickly
3. Avoid requiring JS for essential navigation
4. Use server-side rendering (SSR) or hydration when possible

JavaScript issues often cause indexing failures.

20. Monitor Crawl Stats & Performance Regularly

A technical SEO audit isn’t a one-time task.

Review regularly:

1. Crawl requests
2. Response codes
3. Crawl delays
4. Page fetch frequency
5. Indexing trends

Continuous monitoring ensures long-term SEO stability.

Final Thoughts

A technical SEO audit is essential for discovering hidden issues that block search engines from properly crawling and ranking your website. This 20-step checklist helps you evaluate:

1. Crawlability
2. Indexability
3. Speed
4. Structure
5. Content
6. Security
7. UX
8. Signals

Fixing these issues results in:

✔ Better crawling

✔ Faster indexing

✔ Higher rankings

✔ Improved user experience

✔ Stronger SEO performance