5xx Server Errors

What This Means

One or more pages returned an HTTP 5xx status code — a server-side failure where the server received the request but could not process it successfully. Common codes: 500 (Internal Server Error), 502 (Bad Gateway), 503 (Service Unavailable), and 504 (Gateway Timeout).

Why It Matters for SEO

5xx errors on pages that were previously indexed signal to search engines that the server is unstable or the page is no longer reliably accessible. Googlebot treats repeated 5xx responses as a sign that a URL may have been removed or that the site is experiencing significant issues — it reduces crawl rate and may eventually drop the page from the index if 5xx responses persist.

Unlike 4xx errors (which signal the page does not exist), 5xx errors signal the page might exist but the server failed. Search engines are more patient with 5xx than 4xx, but persistent 5xx responses do result in deindexation.

What the Platform Checks

The platform records the HTTP response code for each crawled URL. Flags any URL returning a 5xx response code during the crawl.

How to Fix It

• 500 Internal Server Error: Check your server error logs immediately — these are usually PHP, Python, or database errors. Review recent deployments or code changes.
• 502/504 Bad Gateway/Timeout: These often indicate server overload, a failing upstream service, or proxy configuration issues. Check server resource utilization and upstream health.
• 503 Service Unavailable: If intentional (maintenance mode), add a Retry-After header to signal to crawlers how long to wait before retrying. Use only temporarily.
• Prevent future 5xx: Monitor uptime and error rates with real-time alerting. Most 5xx issues should be caught by operational monitoring before they affect a crawl.