HTTP Status Code Reference
Free searchable HTTP status code reference — meanings, causes and fixes for 4xx/5xx errors. A handy cheat sheet for developers.
100
Continue
Client should continue with its request; the initial part has been received
101
Switching Protocols
Server agrees to switch protocols, e.g. upgrading to WebSocket
102
Processing
Server has received the request but has not finished processing
103
Early Hints
Server returns partial headers before the final response
200
OK
Request succeeded; the response body contains the requested data
201
Created
Request succeeded and a new resource was created; common with POST
202
Accepted
Request accepted but not yet processed; common for async tasks
204
No Content
Request succeeded with no content returned; common with DELETE
206
Partial Content
Server returns partial content, for range downloads/resumable transfers
301
Moved Permanently
Resource permanently moved to a new URL; SEO weight transfers
302
Found
Resource temporarily redirects to a new URL
304
Not Modified
Resource not modified; use the browser cache
307
Temporary Redirect
Temporary redirect; keeps the original request method
308
Permanent Redirect
Permanent redirect; keeps the original request method
400
Bad Request
Malformed request syntax; the server cannot understand it
401
Unauthorized
Unauthorized — login or credentials required
403
Forbidden
Authenticated but not allowed to access this resource
404
Not Found
The requested resource does not exist
405
Method Not Allowed
Method not allowed, e.g. POST to a GET-only endpoint
408
Request Timeout
Request timeout; the server closed the connection after waiting too long
409
Conflict
Request conflict, e.g. concurrent modification of the same resource
410
Gone
Resource is permanently gone; like 404 but permanent
413
Payload Too Large
Request body too large; the server refuses to process it
414
URI Too Long
Request URI is too long for the server to process
415
Unsupported Media Type
The request media type is not supported by the server
418
I'm a teapot
Easter-egg status code from an April Fools RFC
429
Too Many Requests
Too many requests; rate limit triggered
500
Internal Server Error
Internal server error; the most common server-side error
501
Not Implemented
The server does not support this request method
502
Bad Gateway
Bad gateway; the upstream service returned an invalid response
503
Service Unavailable
Service unavailable; often due to overload or maintenance
504
Gateway Timeout
Gateway timeout; the upstream service did not respond in time
505
HTTP Version Not Supported
The server does not support the HTTP version used
FAQ
Which codes are covered?
All common 1xx-5xx codes with explanations of typical causes and fixes.
Is this a lookup or a tester?
A reference guide — pair it with browser devtools or curl when debugging.
Why do I keep getting 403 but not 401?
401 = not authenticated, 403 = authenticated but not allowed. The guide explains this and similar pairs.