HTTP: Status Codes
Whenever you are typing in URLs in the address bar on the Internet, the chance for an error is eminent. What usually comes back is an HTTP Status Code.

Fortunately, the list of HTTP Status Codes is fairly short.

Successful Transactions

200

The request was fulfilled.

201

The POST request was completed successfully.

202

Request accepted for processing of unknown type. Rare.

203

Request partially fulfilled.

Redirection Transactions

301

The requested resource has been permanently moved to a new URL. Usually ac

companied by Location: new URL, which automatically connects to the new URL.

302

Requested resource found, but at a different URL. You'll get a 302 Redirection if

you omit the trailing slash when pointing at a directory (sometimes called a malformed request).

304

Unmodified data not returned in response to a GET request with the If-Modified-Since field. Occurs when a browser requests data found in cache.

Error Messages

400

Error in request syntax.

401

Request requires an authorization field, and the client did not provide one. This response is accompanied by a list of acceptable authorization schemes use WWW-Authenticate response headers. Error 401 can be part of a client/server dialogue to negotiate encryption and user authentication schemes.

402

The requested operation costs money, and the client did not specify a valid Charge to field.

403

Request for forbidden resource denied.

404

Requested resource not found.

500

The server has encountered an internal error and cannot continue processing your request.

501

Request okay but denied because server doesn't support transaction method.