HTTP Status Codes

Complete reference of HTTP response status codes. Search by code or description to understand what each status means.

1xx Informational

Request received, continuing process
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.
102
Processing
The server has received and is processing the request, but no response is available yet.
103
Early Hints
Used to return some response headers before final HTTP message.

2xx Success

Request successfully received, understood, and accepted
200
OK
The request succeeded. The meaning depends on the HTTP method used.
201
Created
The request succeeded and a new resource was created as a result.
202
Accepted
The request has been received but not yet acted upon.
203
Non-Authoritative Information
The returned metadata is not exactly the same as available from the origin server.
204
No Content
There is no content to send for this request, but the headers may be useful.
205
Reset Content
Tells the client to reset the document view.
206
Partial Content
Only part of a resource is being delivered, usually in response to range headers.

3xx Redirection

Further action needs to be taken to complete the request
300
Multiple Choices
The request has more than one possible response.
301
Moved Permanently
The URL of the requested resource has been changed permanently. The new URL is given in the response.
302
Found
The URI of requested resource has been changed temporarily.
303
See Other
The server sent this response to direct the client to get the requested resource at another URI with a GET request.
304
Not Modified
Used for caching purposes. The response has not been modified, so the client can continue to use the cached version.
307
Temporary Redirect
The server sends this response to direct the client to get the requested resource at another URI with the same method.
308
Permanent Redirect
The resource is now permanently located at another URI, specified by the Location header.

4xx Client Error

Request contains bad syntax or cannot be fulfilled
400
Bad Request
The server cannot process the request due to client error (malformed syntax, invalid request).
401
Unauthorized
Authentication is required and has failed or has not been provided.
403
Forbidden
The client does not have access rights to the content.
404
Not Found
The server cannot find the requested resource. The URL is not recognized.
405
Method Not Allowed
The request method is known by the server but not supported by the target resource.
406
Not Acceptable
The server cannot produce a response matching the acceptable values defined in the request headers.
408
Request Timeout
The server timed out waiting for the request.
409
Conflict
The request conflicts with the current state of the server.
410
Gone
The content has been permanently deleted from server, with no forwarding address.
411
Length Required
Server rejected the request because the Content-Length header is not defined.
413
Payload Too Large
Request entity is larger than limits defined by server.
414
URI Too Long
The URI requested by the client is longer than the server is willing to interpret.
415
Unsupported Media Type
The media format of the requested data is not supported by the server.
422
Unprocessable Entity
The request was well-formed but was unable to be followed due to semantic errors.
429
Too Many Requests
The user has sent too many requests in a given amount of time (rate limiting).
451
Unavailable For Legal Reasons
The user agent requested a resource that cannot legally be provided.

5xx Server Error

Server failed to fulfill a valid request
500
Internal Server Error
The server has encountered a situation it does not know how to handle.
501
Not Implemented
The request method is not supported by the server and cannot be handled.
502
Bad Gateway
The server, while acting as a gateway, received an invalid response from the upstream server.
503
Service Unavailable
The server is not ready to handle the request. Common causes are maintenance or overload.
504
Gateway Timeout
The server, while acting as a gateway, did not get a response in time from the upstream server.
505
HTTP Version Not Supported
The HTTP version used in the request is not supported by the server.
507
Insufficient Storage
The server is unable to store the representation needed to complete the request.
508
Loop Detected
The server detected an infinite loop while processing the request.
511
Network Authentication Required
The client needs to authenticate to gain network access.

Understanding HTTP Status Codes

HTTP status codes are three-digit numbers returned by servers to indicate the result of a client's request. They are grouped into five classes based on the first digit:

  • 1xx (Informational) — Request received, continuing process
  • 2xx (Success) — Request successfully received and processed
  • 3xx (Redirection) — Further action needed to complete request
  • 4xx (Client Error) — Request contains bad syntax or cannot be fulfilled
  • 5xx (Server Error) — Server failed to fulfill a valid request

Most Common Status Codes

While there are many status codes, you'll encounter these most frequently:

200 OK
The request succeeded
301 Moved Permanently
Resource has moved to a new URL
400 Bad Request
Server couldn't understand the request
401 Unauthorized
Authentication required
403 Forbidden
Access denied
404 Not Found
Resource doesn't exist
500 Internal Server Error
Generic server error
502 Bad Gateway
Invalid response from upstream server
503 Service Unavailable
Server temporarily unavailable

Get Alerted on HTTP Errors

Monitor your endpoints 24/7 and get instant alerts when they return error status codes.

Start Monitoring Free

Related Tools

Uptime CalculatorSSL Certificate CheckerIs Website Down?