What are crawl errors and how do you fix them for SEO?

Search engines try to crawl your site and something goes wrong. A page returns a 500 error. A page times out. A page is unreachable. These are crawl errors. They tell Google your site has problems. Many crawl errors harm rankings and prevent pages from being indexed. The more crawl errors you have, the fewer pages Google crawls. You must find and fix crawl errors quickly.

What are crawl errors?

Crawl errors occur when Google tries to crawl a page and encounters a problem. The page might return a 5xx server error. It might timeout and not respond. It might be blocked by robots.txt or redirected endlessly. Any problem that prevents Google from successfully crawling a page is a crawl error.

Crawl errors are different from indexation issues. A page might crawl successfully but not be indexed (due to noindex or other reasons). That is not a crawl error. A crawl error is when the crawl itself fails.

Types of crawl errors

500 Internal Server Error means something on your server is broken. A script crashed. A database query failed. The server cannot process the request. Fix the underlying problem on your server.

503 Service Unavailable means the server is temporarily down. This is normal during maintenance. Fix whatever caused the temporary downtime.

Timeout means the page took too long to respond. Google gave up waiting. This usually means your server is slow or overloaded. Optimize your server or upgrade hosting.

Redirect error means the page redirects incorrectly. Maybe it redirects to itself (infinite loop). Maybe it redirects to a broken page. Fix the redirect chain.

Not found (404) is not technically a crawl error. The page returns 404 correctly. But if this is an important page that should exist, investigate why it is returning 404.

Blocked by robots.txt means robots.txt prevents crawling. This might be intentional (you blocked the page on purpose) or accidental (you blocked too much). Review your robots.txt.

Why crawl errors matter

Crawl errors tell search engines your site has problems. If search engines encounter many crawl errors, it assumes your site is broken and reduces crawl frequency. This means fewer pages get crawled and indexed.

Pages that cannot be crawled cannot be indexed. If an important page returns 500 errors, search engines stop trying to crawl it and removes it from the index.

Crawl errors create a negative signal. Search engines use site health as a ranking factor. A site with many crawl errors looks broken and untrusted. Your rankings suffer.

How to find crawl errors

Use your search engine's webmaster tools (Google Search Console for Google). The Coverage report shows crawl errors. It lists URLs that Google tried to crawl but failed. The error type and number of pages with each error are shown.

Use the Crawl Stats report. This shows how many pages Google crawled on what dates. If crawl volume drops suddenly, you likely have crawl errors.

Use the URL Inspection tool. Enter a specific URL and the tool shows whether it crawled successfully, when it crawled, and what errors it encountered (if any).

Check your server logs. Your hosting provider has access logs showing every request and response. Look for 5xx errors or timeouts.

Common crawl error causes and fixes

Your server is overloaded. Too many requests cause timeouts and 503 errors. Upgrade your hosting or optimize your code to handle more traffic.

A script on your site is broken. A PHP error or database error causes 500 errors. Check your error logs and fix the broken code.

Robots.txt is too restrictive. You accidentally blocked important pages. Review robots.txt and remove overly broad disallow rules.

Redirect chains are broken. Page A redirects to B which redirects to C which is broken. Fix the redirect chain to point directly to the final destination.

A page has a noindex tag. Google crawls it but does not index it due to noindex. If this is intentional, ignore it. If accidental, remove the noindex tag.

Fixing crawl errors

Identify the error type. Different errors need different fixes. 500 errors need server fixes. Timeouts need performance optimization. Redirect errors need redirect fixes.

Fix the underlying problem. For 500 errors, fix the broken code or script. For timeouts, optimize performance. For redirects, fix the chain.

Verify the fix. Use the URL Inspection tool to fetch the page again. Google will re-crawl it and report whether the error is fixed.

Monitor crawl stats. After fixing errors, monitor crawl volume in your webmaster tools. Crawl volume should increase as search engines crawl more pages successfully.

Frequently asked questions