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

Technical SEO can feel like a maze of code, crawl errors, and performance metrics. Fortunately, Semrush Site Audit acts like a lighthouse, spotlighting hidden problems before Google penalizes your site. In this guide we’ll walk through 50 of the most common issues the tool flags and give you clear, actionable fixes you can implement today.

1. Crawlability & Indexing Issues

1.1 Broken Internal Links

• What it is: Links that return 404 or 410 errors.
• Fix: Use a redirect (301) to a relevant page or update the link to the correct URL.

1.2 Orphan Pages

• What it is: Pages with no internal links pointing to them.
• Fix: Add contextual links from related content or include them in the sitemap.

1.3 Duplicate Meta Tags

• What it is: Identical title or meta description across multiple pages.
• Fix: Craft unique, keyword‑rich tags for each page.

1.4 Noindex Tags on Important Pages

• What it is: Pages unintentionally blocked from indexing.
• Fix: Remove noindex from robots meta or HTTP header.

1.5 Incorrect Robots.txt Rules

• What it is: Disallow directives that block essential resources.
• Fix: Review and allow crawling of CSS, JS, and important content directories.

2. Site Speed & Performance

2.1 Large Page Size (> 2 MB)

• Fix: Compress images, enable WebP, and minify CSS/JS.

2.2 Unoptimized Images

• Fix: Resize to display dimensions, use srcset, and serve next‑gen formats.

2.3 Render‑Blocking Resources

• Fix: Inline critical CSS, defer non‑essential JS, and use async where possible.

2.4 Slow Server Response (TTFB > 500 ms)

• Fix: Upgrade hosting, enable caching (Redis, Varnish), and use a CDN.

2.5 Lack of Browser Caching

• Fix: Set Cache‑Control headers with appropriate max‑age values.

3. Mobile‑First Issues

3.1 Text Too Small to Read

• Fix: Use a base font size of 16 px and responsive typography units (rem, vw).

3.2 Tap Targets Too Close

• Fix: Ensure clickable elements have at least 48 × 48 px clickable area.

3.3 Viewport Not Set

• Fix: Add <meta name=viewport content=width=device-width, initial-scale=1>.

3.4 Content Wider Than Screen

• Fix: Use responsive layouts, avoid fixed‑width tables, and apply max-width:100%.

3.5 Missing Mobile‑Friendly Structured Data

• Fix: Implement schema.org markup for BreadcrumbList, FAQ, and Product.

4. HTTPS & Security

4.1 Mixed Content Errors

• Fix: Serve all assets (images, scripts, fonts) over HTTPS.

4.2 Expired SSL Certificate

• Fix: Renew the certificate before expiration.

4.3 Missing HSTS Header

• Fix: Add Strict-Transport-Security: max-age=31536000; includeSubDomains.

4.4 Insecure Cipher Suites

• Fix: Update server configuration to use modern TLS 1.2/1.3 ciphers.

4.5 HTTP to HTTPS Redirect Loops

• Fix: Ensure a single, 301 redirect from HTTP to HTTPS.

5. Structured Data & Rich Snippets

5.1 Missing Required Fields

• Fix: Add all mandatory properties for the chosen schema (e.g., price for Product).

5.2 Invalid JSON‑LD Syntax

• Fix: Validate with Google’s Rich Results Test and correct JSON errors.

5.3 Duplicate Structured Data

• Fix: Keep one block of schema per entity type per page.

5.4 Incorrect Date Formats

• Fix: Use ISO 8601 format (YYYY‑MM‑DD).

5.5 Non‑Indexable Pages with Rich Snippets

• Fix: Ensure the page is crawlable; remove noindex if you want snippets to appear.

6. XML Sitemap Problems

6.1 Sitemap Not Submitted to Google Search Console

• Fix: Submit the sitemap URL via GSC or Bing Webmaster Tools.

6.2 Sitemap Contains 404 URLs

• Fix: Remove dead URLs from the sitemap and regenerate.

6.3 Exceeding 50,000 URLs per Sitemap

• Fix: Split into multiple sitemaps and reference them in a sitemap index.

6.4 Missing lastmod Tags

• Fix: Add lastmod to help crawlers prioritize fresh content.

6.5 No “hreflang” in Sitemap for Multilingual Sites

• Fix: Include xhtml:link rel=alternate hreflang=… entries.

7. Pagination & Canonicalization

7.1 Missing rel="next"/rel="prev"

• Fix: Add these link elements on paginated series.

7.2 Incorrect Canonical Tags on Paginated Pages

• Fix: Point each page to its own URL (self‑canonical) or to the series canonical, as appropriate.

7.3 Duplicate Content Across Filters

• Fix: Use noindex,follow on filtered URLs or apply canonical tags to the base page.

7.4 Infinite URL Parameters

• Fix: Define URL parameter handling in Google Search Console.

7.5 Orphaned Pagination Links

• Fix: Ensure pagination links are reachable from the main category page.

8. Content Issues

8.1 Thin Content (< 300 words)

• Fix: Expand with useful details, FAQs, or related media.

8.2 Duplicate Content Across Subdomains

• Fix: Consolidate with canonical tags or 301 redirects.

8.3 Missing H1 Tag

• Fix: Add a single, keyword‑optimized H1 per page.

8.4 Multiple H1 Tags

• Fix: Keep only one H1; downgrade others to H2/H3.

8.5 Over‑Optimized Anchor Text

• Fix: Use natural, varied anchor text for internal links.

9. International & Localization

9.1 Missing hreflang Annotations

• Fix: Add link rel=alternate hreflang=xx href=URL in or sitemap.

9.2 Wrong Country Targeting in GSC

• Fix: Select the correct target country in Search Console settings.

9.3 Language Mismatch Between Content and Hreflang

• Fix: Align language codes with actual page language.

9.4 Duplicate Meta Descriptions Across Locale Pages

• Fix: Translate and customize meta tags per locale.

9.5 Untranslated Structured Data

• Fix: Provide schema values in the correct language (e.g., name field).

10. Miscellaneous Technical Issues

• 10.1 Incorrect HTTP Status Codes (e.g., 200 on error pages) – implement proper 404/410 responses.
• 10.2 Excessive Redirect Chains – limit to one 301 redirect.
• 10.3 Missing Alt Text on Images – add descriptive alt attributes.
• 10.4 Non‑Canonical URLs for Session IDs – strip parameters via server rules.
• 10.5 Poor Crawl Budget Utilization – block low‑value pages with robots.txt.

FAQ

What is the biggest benefit of using Semrush Site Audit?

It provides a comprehensive, automated scan that surfaces over 200 technical signals in an easy‑to‑read report, letting you prioritize fixes that directly impact crawlability and rankings.

How often should I run a Site Audit?

For most sites, a weekly audit is ideal; larger e‑commerce stores may benefit from daily scans during major updates.

Can I fix all issues myself?

Simple problems like broken links or missing meta tags are DIY‑friendly. Complex server‑level issues (TLS, redirect loops) usually require a developer.

Do these fixes affect my rankings immediately?

After implementing changes, request a recrawl in Google Search Console. Most improvements appear within 1‑2 weeks.

Is there a risk of over‑optimizing after the audit?

Yes. Follow Google’s best‑practice guidelines and avoid excessive redirects, keyword stuffing, or aggressive caching that harms user experience.

Take Action Today

Run a fresh Semrush Site Audit, export the findings, and tackle the issues from the top of this list down. Fixing technical SEO problems not only pleases search engines but also speeds up your site for real users.

Ready to boost your rankings? Start your free Semrush trial and let the audit guide your optimization roadmap.