Help! Fix Crawl-Related Issues for Better SEO Performance

Web crawlers, or spiders, are automated programs used by search engines to scan the web and index content. They follow links to explore websites, including yours, analyzing structure and accessibility. When search engine bots like Googlebot encounter obstacles while crawling your site—such as broken links, server errors, or misconfigured files—your content risks being excluded from search engine indexes. This invisibility directly impacts organic traffic, rankings, and revenue. In this comprehensive guide, we’ll explore how to detect, resolve, and prevent crawlability issues using proven strategies and tools like Google Search Console (GSC) and Semrush’s Site Audit. By the end, you’ll have actionable steps to ensure your site remains fully accessible to crawlers, safeguarding your SEO performance.

Understanding Crawl-Related Issues in SEO

What Are Web Crawlers?

Web crawlers (also called spiders or bots) are automated programs that scan websites to discover and index content for search engines. They follow internal links to map your site’s structure and pages. However, errors like broken links, server downtime, or faulty robots.txt files can block their path, leading to crawl errors.

Why Crawlability Matters

If crawlers can’t access your pages, they won’t be indexed or ranked. This means:

Lost organic search visibility
Wasted crawl budget (the number of pages Googlebot crawls per session)
Declining SEO performance and revenue

According to a study by Moz, websites with unresolved crawl errors experience up to a 40% drop in organic traffic within six months.

Proactively addressing these issues is non-negotiable for sustainable SEO success.

Top SEO Tools to Diagnose Crawl Issues

🔍 Google Search Console (GSC)

Best for: Detecting indexing errors, server issues, and blocked resources. Key Reports:

Coverage Report → Shows 4xx/5xx errors, blocked by robots.txt, and more.
Crawl Stats → Reveals how often Googlebot visits your site.
URL Inspection Tool → Checks real-time crawl status of individual pages.

Screaming Frog SEO Spider

Best for: Deep technical audits (broken links, redirect chains, duplicate content). Key Features:

Crawls up to 500 URLs for free (Paid: Unlimited).
Identifies orphan pages, broken links, and non-indexable pages.
Exports data for further analysis.

Semrush Site Audit

Best for: Automated crawl issue detection with actionable fixes. Key Features:

Detects server errors, duplicate meta tags, and slow pages.
Tracks crawlability issues over time.
Provides priority-based recommendations.

Log File Analysis (Screaming Frog Log Analyzer, Splunk)

Best for: Understanding how search engines interact with your site. Key Insights:

Over-crawled pages (wasting crawl budget).
Pages ignored by bots (potential indexing issues).
Server errors (5xx) and redirect loops.

What Is Crawl-Related Issues?

Web crawlers (or spiders) are automated programs that scan the internet to discover and index content for search engines. They follow links to explore your site’s structure and pages, but errors like broken links, server downtime, or misconfigured files can block their path. When crawlers hit these roadblocks, your pages may go unindexed, leaving them invisible to users searching for your content. Crawl errors fall into two categories:

Site Errors (impacting your entire website)
URL Errors (affecting individual pages)

1. Site Errors: When Your Whole Website Suffers

Site errors disrupt crawlers’ ability to access your entire domain. Here are the most common culprits:

A. Server Errors (5xx HTTP Status Codes)

Server errors occur when your website’s server fails to respond to crawler requests. Common types include:

500 (Internal Server Error): A generic error when the server can’t fulfill a request.
502 (Bad Gateway): A proxy server receives an invalid response.
503 (Service Unavailable): The server is temporarily down for maintenance or overloaded.
504 (Gateway Timeout): The server didn’t respond in time, often due to high traffic.

Why It Matters: Persistent 5xx errors slow crawling rates, and Google may deindex affected URLs. How to Fix:

Monitor server health using tools like Semrush’s Site Audit or Google Search Console (GSC).
Work with your hosting provider to resolve downtime or server overloads.
Use a content delivery network (CDN) to distribute traffic and reduce server strain.

B. DNS Errors

DNS errors happen when crawlers can’t connect to your domain’s IP address. Causes include:

DNS Timeout: The DNS server doesn’t respond quickly enough.
DNS Lookup Failure: The domain name can’t be resolved to an IP address.

Why It Matters: DNS issues can render your entire site inaccessible to bots and users. How to Fix:

Check DNS settings via your domain registrar.
Ensure your domain hasn’t expired.
Use reliable DNS hosting services like Cloudflare or Google Domains.

C. Robots.txt Errors

Your robots.txt file instructs crawlers which pages to access or ignore. Errors arise if:

The file is missing or unreadable.
It accidentally blocks critical pages (e.g., via Disallow: /).

Why It Matters: A faulty robots.txt can block crawlers from indexing your entire site. How to Fix:

Validate your robots.txt using Google’s robots.txt Tester.
Ensure it allows access to key pages and includes your sitemap.

Example of a clean robots.txt:

User-agent: *  
Disallow: /private/  
Allow: /  
Sitemap: https://yourdomain.com/sitemap.xml

2. URL Errors: Page-Specific Crawlability Problems

These errors affect individual pages, often due to technical missteps:

A. 404 Errors (Page Not Found)

404s occur when a page is deleted or moved without redirects. Broken links (internal or external) are a common cause. Why It Matters: 404s waste crawl budget and frustrate users. How to Fix:

301 Redirects: Point broken URLs to relevant, live pages.
Custom 404 Pages: Improve user experience with helpful navigation (e.g., Amazon’s friendly 404 page).
Use Semrush’s Site Audit to find and fix broken links.

B. Soft 404 Errors

A soft 404 occurs when a page returns a “200 OK” status but has little or no content (e.g., empty pages, duplicate content). Why It Matters: Google may deindex these pages, mistaking them for low value. How to Fix:

Add unique, high-quality content.
Use canonical tags to mark duplicates.
Remove or redirect placeholder pages.

C. 403 Forbidden Errors

A 403 error means the server denies access to a page. Causes include:

Incorrect file/folder permissions.
Errors in .htaccess (Apache servers).

How to Fix:

Adjust permissions to allow read access.
Review .htaccess for typos or misconfigurations.

D. Redirect Loops

Redirect loops happen when Page A → Page B → Page A endlessly. Why It Matters: Crawlers abandon the loop, leaving pages unindexed. How to Fix:

Audit redirect chains with Screaming Frog.
Replace circular redirects with direct links.

Step 1: Crawl Issues and how to fix them?

Boost crawl efficiency by first resolving 404/500 errors in Google Search Console’s Coverage Report. Use tools like Screaming Frog or Sitebulb to eliminate broken links, redirect chains, and orphan pages. Finally, analyze server logs to spot over-crawled pages and align bot activity with high-value content.

1. Google Search Console (GSC)

Go to the Coverage Report (under "Indexing") to find:

Errors: Pages with crawl issues (e.g., 404, 500 errors).
Valid with warnings: Pages with issues like soft 404s or blocked resources.
Excluded: Pages not indexed due to crawl issues.

2. Crawling Tools to Identify Crawl Issues

Use tools like Screaming Frog, Sitebulb, or DeepCrawl to crawl your website.
- Look for:
  - Broken links (4xx errors).
  - Server errors (5xx errors).
  - Redirect chains or loops.
  - Orphan pages (pages with no internal links).
  - Duplicate URLs (e.g., with/without trailing slashes, HTTP/HTTPS, or URL parameters).

3. Log File Analysis

Analyze server log files to see how search engine bots are crawling your site.
- Identify:
  - Pages crawled too frequently.
  - Pages not being crawled at all.
  - Crawl errors (e.g., 404, 500).

4. Robots.txt

Check your robots.txt file to ensure it’s not blocking important pages or resources (e.g., CSS, JS).

Step 2: Fix Common Crawl Issues

Here’s how to fix the most common crawl-related issues:

1. Broken Links (4xx Errors)

Identify: Use Screaming Frog or GSC to find broken links.
Fix:
1. Update the link to the correct URL.
2. If the page no longer exists, set up a 301 redirect to a relevant page.
3. Remove the link if it’s unnecessary.

2. Server Errors (5xx Errors)

Identify: Check GSC or server logs for 5xx errors.
Fix:
1. Contact your hosting provider to resolve server issues.
2. Optimize server performance (e.g., increase server resources, fix database errors).

3. Redirect Chains or Loops

Identify: Use Screaming Frog to detect redirect chains (e.g., Page A → Page B → Page C).
Fix:
1. Simplify redirects by linking directly to the final destination.
2. Avoid loops by ensuring redirects don’t point back to themselves.

4. Orphan Pages

Identify: Use a crawler to find pages with no internal links.
Fix:
1. Add internal links to these pages from relevant content.
2. Ensure all important pages are accessible via your site’s navigation.

5. Duplicate URLs

Identify: Use Screaming Frog to find duplicate URLs (e.g., example.com/page and example.com/page/).
Fix:
1. Use canonical tags to specify the preferred version of the URL.
2. Set up 301 redirects to consolidate duplicate pages.
3. Standardize URL structure (e.g., always use trailing slashes or lowercase letters).

6. Blocked Resources

Identify: Check GSC’s Coverage Report for blocked resources (e.g., CSS, JS).
Fix:
1. Update your robots.txt file to allow crawling of critical resources.
2. Ensure your site’s critical resources are not blocked by noindex or disallow rules.

7. Crawl Budget Waste

Identify: Use log file analysis to identify low-value pages being crawled excessively (e.g., pagination, filters).
Fix:
1. Use rel="canonical" or noindex for low-value pages.
2. Block unnecessary pages in robots.txt (if they shouldn’t be indexed).

8. Large or Unoptimized Pages

Identify: Use tools like Screaming Frog to find pages with large file sizes or slow load times.
Fix:
1. Compress images and minify CSS/JS.
2. Enable Gzip compression and browser caching.

Step 3: Monitor and Prevent Future Issues

Regular Audits: Perform regular technical SEO audits using crawling tools.
Monitor GSC: Keep an eye on Google Search Console for new crawl errors.
Fix Issues Promptly: Address crawl issues as soon as they’re identified.
Test Changes: Use staging environments to test fixes before deploying them live.

Pro Tip: Work with developers for technical fixes and test changes in a staging environment before deploying live

Final Thoughts

Crawl-related issues are stealthy SEO killers, but they’re entirely fixable with the right tools and vigilance. By resolving server errors, optimizing your robots.txt, and cleaning up broken links, you’ll ensure search engines can index your content efficiently keeping your rankings and traffic intact. Ready to start? Run a free crawl with Semrush’s Site Audit and tackle crawl errors before they impact your site Or Hire Me