HTTP Status Codes Reference - Complete Status Code Guide
Free online HTTP status codes reference. Search and browse all HTTP response status codes with descriptions, categories, and common use cases.
1xx Informational
The server has received the request headers and the client should proceed.
The server is switching protocols as requested (e.g., WebSocket upgrade).
2xx Success
The request succeeded. Standard response for successful HTTP requests.
The request succeeded and a new resource was created. Common after POST requests.
The request succeeded but there is no content to return. Common for DELETE.
The server is delivering only part of the resource due to a range header.
3xx Redirection
The resource has been permanently moved to a new URL. Use for SEO redirects.
The resource is temporarily at a different URL. Often used in OAuth redirects.
The resource has not been modified since the last request. Use cached version.
Like 302 but preserves the HTTP method. Used in HSTS redirects.
Like 301 but preserves the HTTP method.
4xx Client Error
The server cannot process the request due to invalid syntax or parameters.
Authentication is required. The client must provide valid credentials.
The client does not have permission to access the resource, even with auth.
The requested resource does not exist on the server.
The HTTP method is not supported for the requested resource.
The request conflicts with the current state of the resource.
The resource is permanently gone and will not be available again.
The request body exceeds the server limit.
The media type in the request is not supported by the server.
The request is well-formed but contains semantic errors (used in APIs).
The user has sent too many requests in a given time. Rate limiting.
5xx Server Error
Generic server error. Something unexpected went wrong.
The server received an invalid response from an upstream server.
The server is temporarily unable to handle the request (maintenance/overload).
The upstream server did not respond in time.
What Are HTTP Status Codes?
HTTP status codes are three-digit numbers returned by a web server in response to a client's request. They indicate whether the request was successful, redirected, resulted in a client error, or caused a server error. Status codes are grouped into five categories: 1xx (Informational), 2xx (Success), 3xx (Redirection), 4xx (Client Error), and 5xx (Server Error). Understanding these codes is essential for web developers, API designers, and system administrators who need to build, debug, and monitor web applications and services.
How to Use the HTTP Status Code Reference
- Browse the complete list of HTTP status codes organized by category (1xx through 5xx).
- Use the search field to filter codes by number, name, or description — for example, type '404' or 'redirect'.
- Each status code shows its numeric code, official name, and a concise description of when and how it is used.
- Color-coded categories make it easy to distinguish between success (green), redirection (yellow), client errors (orange), and server errors (red).
- Use this reference while debugging API responses, configuring web servers, or writing error handling logic.
Common Use Cases
- API Development — Choose the correct status codes when designing REST API responses — knowing when to use 201 vs 200, or 400 vs 422, leads to better APIs.
- Debugging HTTP Errors — When an API returns an unexpected status code, quickly look up its meaning to understand whether the issue is client-side or server-side.
- SEO & Redirects — Understand the difference between 301 (permanent) and 302 (temporary) redirects and their impact on search engine optimization.
- Error Page Design — Reference the correct codes when implementing custom error pages for 404, 403, 500, and other common error scenarios.