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Junior

What HTTP message or error codes do you know and what do they mean?

sobes.tech AI

Answer from AI

  • 1xx Informational: The request has been received, and the process is continuing.
    • 100 Continue: The server has received the initial part of the request, and the client should continue sending the rest.
    • 101 Switching Protocols: The server understands and is willing to comply with the request to switch protocols as defined in the Upgrade header.
  • 2xx Success: The action was successfully received, understood, and accepted.
    • 200 OK: The request was successful.
    • 201 Created: The request has been fulfilled, resulting in the creation of a new resource.
    • 204 No Content: The request was successfully processed, but no content is returned. Often used for PUT or DELETE requests.
  • 3xx Redirection: Further action is needed to complete the request.
    • 301 Moved Permanently: The requested resource has been permanently moved to a new URI. Future requests should use the new URI.
    • 302 Found: The requested resource is temporarily located at a different URI.
    • 304 Not Modified: The resource has not been modified since the last request. The client can use its cached version.
  • 4xx Client Error: The request contains bad syntax or cannot be fulfilled.
    • 400 Bad Request: The server cannot process the request due to invalid syntax.
    • 401 Unauthorized: Authentication is required. The client must authenticate.
    • 403 Forbidden: The server understood the request but refuses to authorize it. The client does not have access rights.
    • 404 Not Found: The server cannot find the requested resource.
    • 405 Method Not Allowed: The request method is not supported for the requested resource.
    • 408 Request Timeout: The server did not receive a complete request within the time it was prepared to wait.
    • 409 Conflict: The request could not be completed due to a conflict with the current state of the resource.
    • 429 Too Many Requests: Too many requests have been made in a given amount of time. Used for rate limiting.
  • 5xx Server Error: The server failed to fulfill an apparently valid request.
    • 500 Internal Server Error: An internal server error prevented the request from being fulfilled.
    • 501 Not Implemented: The server does not support the functionality required to fulfill the request.
    • 502 Bad Gateway: The server, acting as a gateway or proxy, received an invalid response from the upstream server.
    • 503 Service Unavailable: The server is currently unavailable (e.g., overloaded or down for maintenance).
    • 504 Gateway Timeout: The server, acting as a gateway or proxy, did not receive a timely response from the upstream server.

Example code to check status:

# Example using curl to get HTTP status
curl -s -o /dev/null -w "%{http_code}\n" https://www.google.com

Sample table (not to be wrapped in code):

Code Category Meaning
200 Success OK
404 Client Error Not Found
500 Server Error Internal Server Error
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