Introduction:
Understanding HTTP status codes is crucial for web developers to diagnose and troubleshoot issues effectively. From indicating successful requests to signaling errors, HTTP status codes convey valuable information about the interactions between clients and servers. In this guide, we'll delve into 18 important HTTP status codes, accompanied by clear examples and detailed descriptions.
200 OK
Description: Signifies that the request has succeeded. The client's request was valid, and the server has fulfilled it.
Example: GET request to retrieve a webpage returns 200 OK if successful.
201 Created
Description: Indicates that the request has been fulfilled, resulting in the creation of a new resource.
Example: After submitting a form to add a new user, the server responds with 201 Created upon successful creation.
204 No Content
Description: Implies that the server successfully processed the request but isn't returning any content.
Example: Deleting a resource where the server responds with 204 No Content upon successful deletion.
400 Bad Request
Description: Indicates that the server cannot process the request due to a client error, such as malformed syntax.
Example: Submitting a POST request with missing required parameters triggers a 400 Bad Request response.
401 Unauthorized
Description: Denotes that the request requires authentication, and the client needs to provide valid credentials.
Example: Accessing a protected resource without logging in prompts a 401 Unauthorized response.
403 Forbidden
Description: Indicates that the server understood the request but refuses to authorize it.
Example: Attempting to access a resource for which the user lacks sufficient permissions results in a 403 Forbidden response.
404 Not Found
Description: Signifies that the server couldn't find the requested resource.
Example: Accessing a URL that doesn't exist on the server returns a 404 Not Found error.
405 Method Not Allowed
Description: Indicates that the method specified in the request (e.g., GET, POST) is not supported for the requested resource.
Example: Attempting to use a POST request on a resource that only accepts GET requests returns a 405 Method Not Allowed response.
500 Internal Server Error
Description: Denotes a generic error message indicating that the server encountered an unexpected condition.
Example: A server-side script encountering an unhandled exception may trigger a 500 Internal Server Error.
502 Bad Gateway
Description: Indicates that the server, while acting as a gateway or proxy, received an invalid response from an upstream server.
Example: If a server acting as a proxy receives an invalid response from the origin server, it returns a 502 Bad Gateway error.
503 Service Unavailable
Description: Signifies that the server is currently unable to handle the request due to temporary overloading or maintenance of the server.
Example: A server undergoing maintenance may return a 503 Service Unavailable response.
504 Gateway Timeout
Description: Denotes that the server, acting as a gateway or proxy, did not receive a timely response from the upstream server.
Example: If the origin server takes too long to respond, a gateway or proxy server may return a 504 Gateway Timeout error.
301 Moved Permanently
Description: Indicates that the requested resource has been permanently moved to a new URL.
Example: Accessing a webpage that has permanently moved to a new domain returns a 301 Moved Permanently response with the new URL.
302 Found
Description: Denotes that the requested resource temporarily resides under a different URL.
Example: A temporary redirect used when a webpage is temporarily moved to another location.
401 Found
Description: Indicates that the requested resource has been temporarily moved to a different URL.
Example: A webpage undergoing maintenance might temporarily redirect to a different URL using a 302 Found response.
307 Temporary Redirect
Description: Similar to 302 Found, indicating that the requested resource has been temporarily moved to a different URL.
Example: A temporary redirect used when a webpage is temporarily moved to another location.
308 Permanent Redirect
Description: Indicates that the requested resource has been permanently moved to a different URL.
Example: Similar to 301 Moved Permanently, but the client should use the new URL for all future requests.
418 I'm a teapot
Description: A humorous status code introduced as an April Fools' joke, indicating that the server refuses the request because it is a teapot.
Example: Attempting to make a coffee machine server brew tea might result in a 418 I'm a teapot response.
