HTTP response codes are three-digit numbers sent by the server to describe the result of a client’s request. They are grouped into five main categories.
📢 1xx – Informational
Temporary responses indicating that the request is being processed.
100 Continue – The server has received the request headers and the client can proceed with the request body.
101 Switching Protocols – The server is changing protocols, such as from HTTP to WebSocket.
✅ 2xx – Success
The request was successfully received, understood and processed.
200 OK – The request succeeded.
201 Created – The request succeeded and a new resource was created.
204 No Content – The request succeeded but there is no content to send in the response.
🔀 3xx – Redirection
Further action is needed to complete the request.
301 Moved Permanently – The resource has a new permanent URL.
302 Found – The resource is temporarily located at a different URL.
304 Not Modified – The resource has not changed since the last request.
⚠️ 4xx – Client Error
The request has invalid data or cannot be processed as sent.
400 Bad Request – The request is malformed.
401 Unauthorized – Authentication is required but missing or invalid.
403 Forbidden – The request is understood but access is denied.
404 Not Found – The resource could not be found.
💥 5xx – Server Error
The server failed to fulfill a valid request.
500 Internal Server Error – A generic error occurred on the server.
502 Bad Gateway – The server received an invalid response from an upstream server.
503 Service Unavailable – The server is temporarily unable to handle the request.