Code 503

HTTP 503 (Service Unavailable) is a server error status code indicating that the server is temporarily unable to handle the request, typically due to overloading or scheduled maintenance. When accompanied by a Retry-After header, it signals to Googlebot to revisit the URL after a specified period without penalizing the site.

HTTP 503 responses are tracked through server log analysis and uptime monitoring tools like Pingdom or StatusCake. Google Search Console's Coverage report flags pages returning 503 as crawl errors, and sustained 503 responses can lead to reduced crawl frequency or de-indexing.