Select a status code to see details.
HTTP Status Code Lookup
Search by code or phrase (e.g., 404, unauthorized, too many requests) and get meaning, common causes, and practical fixes.
Frequently Asked Questions
What are HTTP status code groups?
1xx = informational, 2xx = success, 3xx = redirection, 4xx = client errors, and 5xx = server errors.
Which status codes should I monitor first?
Start with 4xx and 5xx rates, especially 404, 429, 500, 502, 503, and 504. These usually reveal user-facing failures.
Can the same code have different causes?
Yes. For example, 503 can mean maintenance mode, overloaded infrastructure, or a dependency outage.