HTTP Status Codes Reference

Complete list of HTTP response status codes with explanations and common use cases.

1xx — Informational

Code	Name	Description
`100`	Continue	The server has received the request headers and the client should proceed to send the request body.
`101`	Switching Protocols	The server is switching protocols as requested by the client (e.g., upgrading to WebSocket).
`102`	Processing	The server has received the request and is processing it, but no response is available yet (WebDAV).
`103`	Early Hints	Used to return some response headers before the final response, allowing preloading of resources.

2xx — Success

Code	Name	Description
`200`	OK	The request succeeded. The response body contains the requested resource. Most common success response.
`201`	Created	The request succeeded and a new resource was created. Typically returned after POST requests.
`202`	Accepted	The request has been accepted for processing, but processing has not been completed (async operations).
`204`	No Content	The request succeeded but there's no content to return. Common for DELETE requests.
`206`	Partial Content	The server is returning partial content as requested by the Range header. Used for resumable downloads.

3xx — Redirection

Code	Name	Description
`301`	Moved Permanently	The resource has been permanently moved to a new URL. Browsers will cache this redirect. SEO-friendly.
`302`	Found	The resource has been temporarily moved to a different URL. The original URL should still be used.
`303`	See Other	The response can be found at another URL using GET. Often used after POST to redirect to a result page.
`304`	Not Modified	The resource has not been modified since the last request. The client can use its cached version.
`307`	Temporary Redirect	Like 302, but the request method must not change. POST stays POST.
`308`	Permanent Redirect	Like 301, but the request method must not change. POST stays POST.

4xx — Client Errors

Code	Name	Description
`400`	Bad Request	The server cannot process the request due to malformed syntax, invalid parameters, or bad formatting.
`401`	Unauthorized	Authentication is required and has failed or not been provided. Include a WWW-Authenticate header.
`403`	Forbidden	The server understood the request but refuses to authorize it. Authentication won't help.
`404`	Not Found	The server cannot find the requested resource. The most famous HTTP error code.
`405`	Method Not Allowed	The HTTP method is not allowed for this resource (e.g., POST on a read-only endpoint).
`408`	Request Timeout	The server timed out waiting for the request from the client.
`409`	Conflict	The request conflicts with the current state of the resource (e.g., duplicate entry, edit conflict).
`410`	Gone	The resource has been permanently deleted and will not be available again. Unlike 404, this is intentional.
`413`	Payload Too Large	The request body exceeds the server's size limits (e.g., file upload too large).
`415`	Unsupported Media Type	The server does not support the media type of the request body (check Content-Type header).
`422`	Unprocessable Entity	The request is syntactically correct but semantically invalid (e.g., validation errors).
`429`	Too Many Requests	The client has sent too many requests in a given time period (rate limiting). Check Retry-After header.
`451`	Unavailable for Legal Reasons	The resource is unavailable due to legal demands (censorship, DMCA, etc.).

5xx — Server Errors

Code	Name	Description
`500`	Internal Server Error	A generic server error. Something went wrong but the server can't be more specific about the cause.
`501`	Not Implemented	The server does not support the functionality required to fulfill the request.
`502`	Bad Gateway	The server acting as a gateway received an invalid response from the upstream server.
`503`	Service Unavailable	The server is temporarily unable to handle the request (overloaded, maintenance). Check Retry-After.
`504`	Gateway Timeout	The server acting as a gateway did not receive a timely response from the upstream server.