HTTP Status Codes
Look up the meaning of every common HTTP response status code.
Showing 30 of 30 entries
| Code | Name | Category | Description |
|---|---|---|---|
100 | Continue | 1xx Informational | The server received the request headers and the client should proceed to send the body. |
101 | Switching Protocols | 1xx Informational | The server is switching protocols as requested by the client (e.g. to WebSocket). |
200 | OK | 2xx Success | The request succeeded. The meaning depends on the HTTP method used. |
201 | Created | 2xx Success | The request succeeded and a new resource was created as a result. |
202 | Accepted | 2xx Success | The request has been accepted for processing, but processing is not complete. |
204 | No Content | 2xx Success | The server successfully processed the request and is not returning any content. |
206 | Partial Content | 2xx Success | The server is delivering only part of the resource due to a range header sent by the client. |
301 | Moved Permanently | 3xx Redirection | The resource has permanently moved to a new URL given in the response. |
302 | Found | 3xx Redirection | The resource temporarily resides at a different URL. The client should keep using the original URL for future requests. |
304 | Not Modified | 3xx Redirection | The cached version of the resource is still valid; the client can use its copy. |
307 | Temporary Redirect | 3xx Redirection | The request should be repeated at another URL using the same HTTP method. |
308 | Permanent Redirect | 3xx Redirection | The resource is permanently at a new URL and the same method must be used. |
400 | Bad Request | 4xx Client Error | The server cannot process the request due to a client error such as malformed syntax. |
401 | Unauthorized | 4xx Client Error | Authentication is required and has failed or has not been provided. |
403 | Forbidden | 4xx Client Error | The server understood the request but refuses to authorize it. |
404 | Not Found | 4xx Client Error | The server cannot find the requested resource. This is the most common error code. |
405 | Method Not Allowed | 4xx Client Error | The request method is known by the server but is not supported by the target resource. |
408 | Request Timeout | 4xx Client Error | The server timed out waiting for the request from the client. |
409 | Conflict | 4xx Client Error | The request conflicts with the current state of the target resource. |
410 | Gone | 4xx Client Error | The resource is no longer available and will not be available again. |
413 | Payload Too Large | 4xx Client Error | The request entity is larger than limits defined by the server. |
415 | Unsupported Media Type | 4xx Client Error | The media format of the requested data is not supported by the server. |
418 | I'm a teapot | 4xx Client Error | An April Fools' joke from RFC 2324; the server refuses to brew coffee because it is a teapot. |
422 | Unprocessable Entity | 4xx Client Error | The request was well-formed but could not be processed due to semantic errors (common in validation). |
429 | Too Many Requests | 4xx Client Error | The user has sent too many requests in a given amount of time (rate limiting). |
500 | Internal Server Error | 5xx Server Error | A generic error message returned when the server encounters an unexpected condition. |
501 | Not Implemented | 5xx Server Error | The server does not support the functionality required to fulfil the request. |
502 | Bad Gateway | 5xx Server Error | The server, acting as a gateway, received an invalid response from the upstream server. |
503 | Service Unavailable | 5xx Server Error | The server is not ready to handle the request, often due to maintenance or overload. |
504 | Gateway Timeout | 5xx Server Error | The server, acting as a gateway, did not get a response in time from the upstream server. |
Understanding HTTP Status Codes
Every HTTP response carries a three-digit status code that tells the client how the request went. The first digit defines the class of response, and knowing these classes makes debugging APIs and web servers far faster.
The five classes
- 1xx Informational â request received, continuing
- 2xx Success â the request succeeded
- 3xx Redirection â further action needed
- 4xx Client Error â the request was wrong
- 5xx Server Error â the server failed
The ones you will meet most
200 OK, 301/302 redirects, 401 and 403 for auth, 404 Not Found, 429 rate limiting, and 500/502/503 for server problems are the codes you will encounter daily as a developer.
4xx vs. 5xx â whose fault is it?
A 4xx code means the client made a mistake â a bad URL, missing authentication, or invalid payload â so the fix is in the request. A 5xx code means the server failed to fulfil a valid request, so the fix is on the server side. Telling them apart is the first step in any debugging session.
Frequently Asked Questions
Common questions about the HTTP Status Codes Reference.
What do the HTTP status code classes mean?
1xx is informational, 2xx is success, 3xx is redirection, 4xx is a client error, and 5xx is a server error.
What is the difference between 401 and 403?
401 Unauthorized means authentication is required or has failed, while 403 Forbidden means you are authenticated but not allowed to access the resource.
Is this reference free to use?
Yes. It is a free, searchable reference with no sign-up required.