HTTP status codes are three-digit numbers returned by a server to indicate the outcome of a request. They are categorized into five classes based on the first digit:

1xx: Informational

  • 📌 100 Continue: The client should continue the request.
  • 📌 101 Switching Protocols: The server agrees to switch protocols.

2xx: Success

  • ✅ 200 OK: Request successfully processed.
    200_OK
  • ✅ 201 Created: Resource created on the server.
  • ✅ 204 No Content: Request successful but no content returned.

3xx: Redirection

  • 🔄 301 Moved Permanently: Permanent redirect.
    301_Redirect
  • 🔄 302 Found: Temporary redirect.
  • 🔄 307 Temporary Redirect: Request should be repeated to the same method.

4xx: Client Error

  • ⚠️ 400 Bad Request: Invalid request syntax.
    400_Error
  • ⚠️ 401 Unauthorized: Authentication required.
  • ⚠️ 403 Forbidden: Server拒绝访问.
    403_Forbidden
  • ⚠️ 404 Not Found: Resource不存在.
    404_Not_Found

5xx: Server Error

  • ❌ 500 Internal Server Error: Unexpected server error.
    500_Error
  • ❌ 502 Bad Gateway: Invalid response from upstream server.
  • ❌ 503 Service Unavailable: Server temporarily unable to handle request.

For more details on HTTP methods related to status codes, visit Documentation/en/HTTP_Methods. 📚