50 Technical SEO Issues Semrush Site Audit Can Find (and How to Fix Them)

By Azon Vault On Apr 28, 2026

Introduction

When your website’s traffic stalls, the culprit is often hidden in the code. Semrush’s Site Audit crawls every page, flagging technical SEO problems that stop search engines from indexing or ranking your content. This guide walks you through 50 of the most common issues Semrush detects and gives clear, step‑by‑step fixes so you can boost crawlability, speed, and rankings.

Core Crawl & Indexing Issues

1. Broken Internal Links

Impact: Wastes crawl budget and creates a poor user experience.

Open the “Crawlability” report.
Export the list of 404 internal URLs.
Redirect with a 301 to the correct page or update the linking anchor.

2. Orphan Pages

Impact: Pages never discovered by Google.

Identify pages with zero internal links.
Add contextual links from related content or the sitemap.

3. Duplicate Content (Meta Tags & Body)

Impact: Dilutes ranking power.

Use canonical tags pointing to the preferred version.
Or consolidate similar pages into a single, comprehensive resource.

4. Blocked Resources (robots.txt)

Impact: Prevents Googlebot from accessing CSS, JS, or images needed for rendering.

Review the robots.txt file for disallowed directories.
Allow essential assets and test with Test robots.txt in Search Console.

5. Non‑Indexable Pages (noindex tag)

Impact: Valuable content stays hidden.

Audit pages flagged with noindex.
Remove the tag from pages you want indexed, or keep it on thin / duplicate pages.

Performance & Speed Problems

6. Slow Page Load Time

Impact: Higher bounce rates, ranking penalty.

Compress images (WebP or AVIF).
Enable server‑side compression (GZIP/Brotli).
Implement lazy loading for below‑the‑fold content.

7. Large HTML Documents

Impact: Increases download size and parsing time.

Trim unnecessary code, comments, and whitespace.
Split massive content into paginated sections.

8. Unminified CSS/JS

Impact: Extra bytes and render‑blocking.

Minify files using tools like Terser (JS) or cssnano (CSS).
Combine critical CSS inline and defer the rest.

9. Render‑Blocking Resources

Impact: Delays First Contentful Paint.

Use rel=preload for key assets.
Add async or defer to script tags.

10. Poor Caching Policy

Impact: Users and bots repeatedly download unchanged files.

Set Cache‑Control headers (e.g., max‑age=31536000 for static assets).
Leverage a CDN to serve cached copies globally.

Mobile & Usability Concerns

11. Missing Viewport Meta Tag

Impact: Mobile rendering issues.

Add <meta name=viewport content=width=device-width, initial-scale=1> to the <head>.

12. Touch‑Element Too Close

Impact: Users accidentally tap the wrong link.

Increase spacing to at least 48 px between interactive elements.

13. Content Width Exceeds Screen

Impact: Horizontal scrolling hurts UX.

Ensure images, tables, and iframes are responsive (max‑width: 100%).

14. Unoptimized Mobile Speed

Impact: Mobile‑first indexing favors fast pages.

Apply the same performance fixes as desktop, focusing on mobile‑specific assets.

15. Insecure Mixed Content

Impact: Browser warnings and crawl issues.

Serve all resources over HTTPS; update hard‑coded HTTP URLs.

Structural & Semantic Errors

16. Missing H1 Tag

Impact: Reduces topical relevance.

Ensure each page has a single, descriptive <h1>.

17. Multiple H1 Tags

Impact: Confuses search engines.

Limit H1 to one per page; use H2‑H6 for sub‑headings.

18. Improper Heading Hierarchy

Impact: Weak semantic structure.

Maintain a logical order (H1 → H2 → H3…).

19. Missing Alt Text on Images

Impact: Lost SEO value and accessibility.

Write concise, keyword‑rich alt attributes for all images.

20. Duplicate Title Tags

Impact: Title confusion in SERPs.

Craft unique, 50‑60 character titles for each page.

URL & Site Architecture Issues

21. Non‑Friendly URLs (Parameters, Session IDs)

Impact: Dilutes link equity.

Rewrite URLs to be static and keyword‑rich.

22. Excessive URL Depth

Impact: Harder for crawlers to reach content.

Keep URL structure shallow (max 3‑4 subfolders).

23. Inconsistent Trailing Slashes

Impact: Creates duplicate pages.

Choose a canonical version (with or without slash) and set redirects.

24. Unnecessary WWW vs non‑WWW

Impact: Split authority.

Pick one version, set 301 redirects, and update internal links.

25. Missing XML Sitemap

Impact: Crawlers miss important pages.

Generate a clean sitemap (no noindex pages) and submit to Search Console.

Security & Accessibility

26. No HTTPS

Impact: Rankings penalty and trust loss.

Obtain an SSL certificate, enable HTTPS, and redirect HTTP → HTTPS.

27. Invalid SSL Certificate

Impact: Crawl errors.

Renew or correct the certificate chain.

28. Missing Structured Data

Impact: Missed rich‑result opportunities.

Implement FAQ, Breadcrumb, or Product schema where relevant.

29. Incorrect Structured Data Markup

Impact: Google may ignore or penalize.

Validate with Google’s Rich Results Test and fix errors.

30. Accessibility Violations (ARIA, Contrast)

Impact: Legal risk & bad UX.

Use proper ARIA roles and maintain a contrast ratio > 4.5:1.

Advanced Crawl Errors

31. Server Errors (5xx)

Impact: Pages drop from index.

Check server logs, fix misconfigurations, and ensure uptime.

32. Client Errors (4xx) Beyond 404

Impact: Crawl budget waste.

Address 403, 401, and 410 responses appropriately—use 410 for permanently removed content.

33. Soft 404s

Impact: Search engines think content is missing.

Return proper 404/410 status for thin “Page not found” pages.

34. Redirect Chains & Loops

Impact: Slows crawl and dilutes link equity.

Limit redirects to a single 301 hop; remove loops.

35. Too Many Redirects

Impact: Wastes crawl budget.

Consolidate to one final URL per page.

International & Language Issues

36. Missing hreflang Tags

Impact: Wrong language version shown to users.

Add hreflang annotations for each locale and a self‑referencing tag.

37. Inconsistent Language Declarations

Impact: Crawlers can’t determine page language.

Set lang attribute in the <html> tag.

38. Duplicate International Content

Impact: Competes against itself.

Use canonical tags combined with hreflang.

Content & Metadata Gaps

39. Thin Content (<300 words)

Impact: Low ranking potential.

Expand with unique, valuable information and add internal links.

40. Missing Meta Description

Impact: Lower click‑through rate.

Write compelling 150‑160 character descriptions with target keyword.

41. Duplicate Meta Descriptions

Impact: Missed SERP differentiation.

Craft unique descriptions for each page.

42. Over‑Optimized Anchor Text

Impact: Risk of a Penguin penalty.

Vary anchor text; use branded or natural language.

43. Missing Open Graph / Twitter Card Tags

Impact: Poor social sharing preview.

Add OG title, description, and image tags.

Indexation & Crawl Budget Optimization

44. Low Crawl Rate Limit

Impact: Search engines crawl fewer pages.

In Search Console, raise the crawl rate if server can handle it.

45. Excessive Low‑Value Pages (e.g., tag archives)

Impact: Wastes crawl budget.

Noindex paginated archives and tag pages that add little value.

46. Unnecessary Parameter URLs

Impact: Duplicate content.

Use URL parameter handling in Search Console or canonical tags.

47. Crawl Budget Loss from 404 Spam

Impact: Bots waste time on dead links.

Regularly audit and 301‑redirect or delete spammy URLs.

48. Unoptimized Pagination

Impact: Dilutes link equity.

Implement rel=next/prev or use view‑all pages with canonical.

Miscellaneous Technical Problems

49. Incorrect MIME Types

Impact: Browsers may block resources.

Serve CSS as text/css, JS as application/javascript.

50. Missing favicon.ico

Impact: Minor branding loss.

Add a favicon and reference it in the <head>.

Conclusion

Semrush Site Audit is a powerful diagnostic engine. By systematically tackling the 50 issues above—starting with crawl errors, then performance, mobile, and structural problems—you’ll unlock more crawl budget, improve user experience, and climb the rankings. Remember: SEO is an ongoing process. Schedule regular audits, prioritize fixes, and monitor performance metrics to stay ahead of algorithm changes.

FAQ

Q1: How often should I run a Semrush Site Audit?
At least once a month for dynamic sites, and after major updates or redesigns.

Q2: Do I need to fix every issue?
Prioritize high‑severity items (crawl errors, security, speed) that directly affect rankings and user experience.

Q3: Can I automate redirects?
Yes—use server‑level rewrite rules (e.g., .htaccess, nginx) or a CMS plugin to batch‑process 301 redirects.

Q4: Will fixing these issues guarantee higher rankings?
They remove technical barriers. Combine with quality content and backlinks for the best results.

Q5: Where can I learn more about structured data?
Refer to Google’s Structured Data Guidelines for detailed implementation advice.

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