Understanding HTTP Status Codes: A Complete Guide to Every Response

HTTP Status Codes Overview

When a client accesses a resource via HTTP or FTP, the server returns a numeric status code indicating the result of the request. These codes appear in server logs and may be shown in browsers or FTP clients, helping identify success or the exact reason for failure.

Classification

HTTP status codes are grouped into five classes:

1xx – Informational

2xx – Successful

3xx – Redirection

4xx – Client Error

5xx – Server Error

1xx Informational

100 Continue – Indicates that the initial part of the request has been received and the client should continue.

101 Switching Protocols – Server agrees to switch protocols as requested by the client.

2xx Successful

200 OK – The request has succeeded.

201 Created – The request resulted in a new resource being created, with its URI typically provided in the Location header.

202 Accepted – The request has been accepted for processing, but the processing is not yet complete.

203 Non-Authoritative Information – The returned meta‑information is from a third‑party source.

204 No Content – The server successfully processed the request but is not returning any content.

205 Reset Content – The client should reset the document view.

206 Partial Content – The server is delivering only part of the resource due to a range header.

3xx Redirection

300 Multiple Choices – Multiple options for the resource are available.

301 Moved Permanently – The resource has a new permanent URI.

302 Found – The resource resides temporarily under a different URI.

303 See Other – The response to the request can be found under a different URI using a GET method.

304 Not Modified – The resource has not been modified since the version specified by the request headers.

305 Use Proxy – The requested resource must be accessed through the proxy given by the Location header.

307 Temporary Redirect – The request should be repeated with another URI, but future requests can still use the original URI.

4xx Client Error

400 Bad Request – The request could not be understood due to malformed syntax.

401 Unauthorized – Authentication is required and has failed or not yet been provided.

402 Payment Required – Reserved for future use.

403 Forbidden – The server understood the request but refuses to authorize it.

404 Not Found – The server cannot find the requested resource.

405 Method Not Allowed – The request method is known by the server but is not supported by the target resource.

406 Not Acceptable – The requested resource is capable of generating only content not acceptable according to the Accept headers sent in the request.

407 Proxy Authentication Required – The client must first authenticate itself with the proxy.

408 Request Timeout – The client did not produce a request within the time that the server was prepared to wait.

409 Conflict – The request could not be completed due to a conflict with the current state of the resource.

410 Gone – The resource requested is no longer available and will not be available again.

411 Length Required – The request did not specify the length of its content, which is required by the server.

412 Precondition Failed – The server does not meet one of the preconditions that the requester put on the request.

413 Payload Too Large – The request entity is larger than limits defined by the server.

414 URI Too Long – The URI provided was too long for the server to process.

415 Unsupported Media Type – The request entity has a media type which the server or resource does not support.

416 Range Not Satisfiable – The client has asked for a portion of the file, but the server cannot supply that portion.

417 Expectation Failed – The server cannot meet the requirements of the Expect request‑header field.

5xx Server Error

500 Internal Server Error – The server encountered an unexpected condition that prevented it from fulfilling the request.

501 Not Implemented – The server does not support the functionality required to fulfill the request.

502 Bad Gateway – The server, while acting as a gateway or proxy, received an invalid response from the upstream server.

503 Service Unavailable – The server is currently unable to handle the request due to temporary overload or maintenance.

504 Gateway Timeout – The server did not receive a timely response from an upstream server.

505 HTTP Version Not Supported – The server does not support the HTTP protocol version used in the request.

"100" : Continue
"101" : Switching Protocols
"200" : OK
"201" : Created
"202" : Accepted
"203" : Non-Authoritative Information
"204" : No Content
"205" : Reset Content
"206" : Partial Content
"300" : Multiple Choices
"301" : Moved Permanently
"302" : Found
"303" : See Other
"304" : Not Modified
"305" : Use Proxy
"307" : Temporary Redirect
"400" : Bad Request
"401" : Unauthorized
"402" : Payment Required
"403" : Forbidden
"404" : Not Found
"405" : Method Not Allowed
"406" : Not Acceptable
"407" : Proxy Authentication Required
"408" : Request Time-out
"409" : Conflict
"410" : Gone
"411" : Length Required
"412" : Precondition Failed
"413" : Request Entity Too Large
"414" : Request-URI Too Large
"415" : Unsupported Media Type
"416" : Requested range not satisfiable
"417" : Expectation Failed
"500" : Internal Server Error
"501" : Not Implemented
"502" : Bad Gateway
"503" : Service Unavailable
"504" : Gateway Time-out
"505" : HTTP Version not supported