Crawl errors occur when a search engine crawler attempts to access a page and encounters a problem — and left unaddressed, they can meaningfully affect indexing and rankings. Here's how to understand and resolve the most common types.
404 Not Found Errors
These occur when a crawler follows a link to a page that no longer exists. A few 404s are normal, but a large volume — particularly for pages with existing backlinks or that were previously ranking — represents lost value worth addressing through proper redirects to relevant existing content.
Server Errors (5xx)
These indicate your server failed to respond properly to the crawler's request, often due to server overload, misconfiguration, or temporary downtime. Frequent server errors can meaningfully reduce crawl frequency and trust over time, making prompt investigation important.
Redirect Errors and Chains
Redirect loops (where a redirect eventually points back to itself) or excessively long redirect chains both waste crawl resources and can prevent a crawler from ever successfully reaching the intended final destination.
Soft 404s
A soft 404 occurs when a page returns a normal success status but actually displays "not found" or empty content — confusing for both crawlers and users, since the technical signal doesn't match the actual page experience.
Blocked Resource Errors
These occur when a crawler is blocked, often accidentally through robots.txt misconfiguration, from accessing resources needed to fully render or understand a page.
How to Systematically Address Crawl Errors
- Regularly review crawl error reports rather than waiting for a ranking issue to trigger investigation
- Prioritize fixing errors on pages with genuine value — existing backlinks, prior rankings, or current traffic
- Implement proper redirects for permanently moved or removed content, rather than leaving broken links unaddressed
- Address the root cause for recurring server errors, rather than treating each occurrence as an isolated incident
Catch crawl errors before they compound. SeoWolf's Broken Links Finder and Server Status Checker help you identify and prioritize these issues systematically.