Googlebot Crawl Issues? Mueller Cites Server Errors
▼ Summary
– A Reddit thread discussed a 90% drop in Googlebot crawl requests after broken hreflang URLs returning 404s were deployed.
– Google’s John Mueller suggested rapid crawl drops are more likely caused by server issues (429/500/503 or timeouts) than 404s.
– Mueller advised checking logs for server-side errors or CDN blocks, as crawl rates recover automatically once resolved.
– Google’s official guidance recommends using 500, 503, or 429 responses—not 404s—to temporarily throttle crawling.
– The article emphasizes verifying server responses and using Search Console’s Crawl Stats to diagnose sudden crawl declines.
When Googlebot suddenly stops crawling your site, server errors, not 404s, are often the real culprit. That’s the key takeaway from a recent discussion involving Google’s John Mueller, who responded to a case where crawl rates plummeted overnight.
The issue began when a website accidentally deployed broken hreflang URLs in HTTP headers, resulting in a flood of 404 errors as Googlebot attempted to fetch them. Within 24 hours, crawl requests dropped by roughly 90%, though indexed pages remained stable. While the poster assumed the 404s were to blame, Mueller suggested otherwise.
Mueller emphasized that 404 errors alone rarely trigger such a rapid decline in crawl activity. Instead, he pointed to server-side issues like 429 (Too Many Requests), 500 (Internal Server Error), or 503 (Service Unavailable) responses as more likely causes. Timeouts could also play a role. His advice? Dig deeper into server logs to confirm whether these errors, not just 404s, were the real problem.
Google’s official guidance supports this approach. If you need to temporarily slow down crawling, returning a 500, 503, or 429 is the recommended method. Unlike 404s, which Googlebot typically retries, these server-side signals prompt an immediate adjustment in crawl behavior.
For site owners facing a sudden crawl drop, Mueller’s advice is clear: Review server logs and Search Console’s Crawl Stats for spikes in 429, 500, or 503 errors.
Recovery isn’t instant, but Mueller noted that once server issues are resolved, crawl rates should normalize on their own, though there’s no fixed timeline. Patience and thorough troubleshooting are key.
(Source: Search Engine Journal)
