HTTP Status Code Reference
Complete HTTP status code reference with descriptions, use cases, and examples. Search and filter all HTTP status codes โ 1xx informational, 2xx success, 3xx redirection, 4xx client errors, 5xx server errors. Free online HTTP status code lookup.
Frequently Asked Questions
What are HTTP status codes?
HTTP status codes are three-digit numbers returned by a server in response to a client's HTTP request. They indicate whether the request was successful, encountered an error, or requires further action. Status codes are defined by the HTTP specification (RFC 7231) and are grouped into five categories based on their first digit.
What do the different categories mean?
1xx (Informational): Request received, continuing process. 2xx (Success): Request successfully received and processed. 3xx (Redirection): Further action needed to complete the request. 4xx (Client Error): Request contains bad syntax or cannot be fulfilled. 5xx (Server Error): Server failed to fulfill a valid request.
Which status codes are most commonly used?
The most common codes are: 200 OK (successful GET/POST), 201 Created (successful POST that created a resource), 204 No Content (successful DELETE), 301 Moved Permanently (permanent redirect), 302 Found (temporary redirect), 400 Bad Request (malformed syntax), 401 Unauthorized (authentication required), 403 Forbidden (authenticated but not allowed), 404 Not Found (resource doesn't exist), 500 Internal Server Error (server crash), 502 Bad Gateway (upstream failure), 503 Service Unavailable (server overloaded).
What is the difference between 401 and 403?
401 Unauthorized means the client has not authenticated - they need to provide credentials (login). 403 Forbidden means the client is authenticated but does not have permission to access the resource. In other words: 401 = "Who are you?" and 403 = "I know who you are, but you can't do that."
What is the difference between 301 and 302?
301 Moved Permanently tells search engines and browsers that the resource has permanently moved to a new URL - they should update their bookmarks and indexes. 302 Found is a temporary redirect - the resource is temporarily at a different URL, but future requests should still go to the original URL. Use 301 for permanent URL changes (SEO benefit) and 302 for temporary situations like A/B testing or maintenance.
Is this tool free?
Yes, completely free with no sign-up required. This is a static reference page - no data is sent to any server.