link: HTTP

HTTP Status Codes

HTTP status codes are three-digit numbers issued by servers to indicate the result of a client’s request. These codes are organized into categories reflecting the type of response provided.

1xx - Informational Responses

These codes indicate that the request initiated by the client was received and is being processed.

Info

• 100 Continue 🛈 The server has received the initial part of the request and is indicating that the client should continue.

2xx - Success

These codes signify that the client’s request was successfully received, understood, and accepted.

Success

• 200 OK ✅ The standard response for successful HTTP requests.
• 201 Created ✅ A new resource has been created as a result of the request.
• 204 No Content ✅ The request was successful but there is no content to return.

3xx - Redirection

This group of status codes indicates that further action needs to be taken by the client in order to complete the request.

Redirection

• 301 Moved Permanently 🔃 The resource is permanently moved to a new URL provided in the response.
• 302 Found 🔃 Directs the client to a temporarily moved resource.
• 304 Not Modified 🔃 Indicates that the resource has not been modified and can be retrieved from the client’s cache.

4xx - Client Errors

These codes are used when the request contains incorrect syntax or cannot be fulfilled.

Client Errors

• 400 Bad Request 🚫 The request cannot be processed due to bad syntax.
• 401 Unauthorized 🚫 Authentication is required and has failed or has not been provided.
• 403 Forbidden 🚫 The request is understood but the server refuses to authorize it.
• 404 Not Found 🚫 The server can’t find the requested resource.

5xx - Server Errors

These indicate errors with the server’s ability to process the request.

Server Errors

• 500 Internal Server Error 🛠️ A generic error message when the server fails unexpectedly.
• 502 Bad Gateway 🛠️ The server received an invalid response from an upstream server while acting as a gateway or proxy.
• 503 Service Unavailable 🛠️ The server is currently unable to handle the request due to temporary overload or scheduled maintenance.
• 504 Gateway Timeout 🛠️ The server did not receive a timely response from an upstream server.

Understanding these status codes is crucial for diagnosing issues in HTTP communications and ensuring effective web and application development.