Free HTTP Status Code Helper calculator with clear step-by-step results.
Classifies a status code and answers the two operational questions that matter: whether a client should retry it, and whether it is cacheable without explicit headers. The volume figure converts an error rate into requests per minute, which is what makes an alert threshold meaningful.
Status class
Class = floor(code / 100), giving 1xx through 5xx
Affected volume
Requests per minute = total RPM x error rate
408, 425, 429 and most 5xx responses, always with exponential backoff and jitter. 501 is not retryable because the server will never implement the method, and 4xx generally means the request itself is wrong.
Yes - 404 and 410 are cacheable by default under HTTP semantics, which surprises people debugging a resource that has since been created. Send explicit cache headers if that is not what you want.