- 100 - Continue
A status code of 100 indicates that (usually the first) part of a request has been received without any problems, and that the rest of the request should now be sent. - 101 - Switching Protocols
HTTP 1.1 is just one type of protocol for transferring data on the web, and a status code of 101 indicates that the server is changing to the protocol it defines in the "Upgrade" header it returns to the client. For example, when requesting a page, a browser might receive a statis code of 101, followed by an "Upgrade" header showing that the server is changing to a different version of HTTP.
Successful
- 200 - OK
The 200 status code is by far the most common returned. It means, simply, that the request was received and understood and is being processed. - 201 - Created
A 201 status code indicates that a request was successful and as a result, a resource has been created (for example a new page). - 202 - Accepted
The status code 202 indicates that server has received and understood the request, and that it has been accepted for processing, although it may not be processed immediately. - 203 - Non-Authoritative Information
A 203 status code means that the request was received and understood, and that information sent back about the response is from a third party, rather than the original server. This is virtually identical in meaning to a 200 status code. - 204 - No Content
The 204 status code means that the request was received and understood, but that there is no need to send any data back. - 205 - Reset Content
The 205 status code is a request from the server to the client to reset the document from which the original request was sent. For example, if a user fills out a form, and submits it, a status code of 205 means the server is asking the browser to clear the form. - 206 - Partial Content
A status code of 206 is a response to a request for part of a document. This is used by advanced caching tools, when a user agent requests only a small part of a page, and just that section is returned.