# HTTP Codes and Methods ## HTTP Error Codes HTTP error codes are standard response status codes used by web servers to indicate the outcome of a client's request. These codes are grouped into different categories, including informational, success, redirection, client errors, and server errors. ### **1xx (Informational Responses)** | Code | Description | | --------------------------- | --------------------------------------------------------------------------------------------- | | **100 Continue** | The request has been received, and the server is waiting for the continuation of the request. | | **101 Switching Protocols** | The server agrees to switch the protocol as requested by the client. | ### **2xx (Success Responses)** | Code | Description | | ----------------------- | ----------------------------------------------------------------- | | **200 OK** | The request has been successfully processed. | | **201 Created** | The request resulted in the creation of a new resource. | | **204 No Content** | The request was successful, but the response contains no content. | | **206 Partial Content** | The response contains only a portion of the requested data. | ### **3xx (Redirection)** | Code | Description | | -------------------------- | --------------------------------------------------------------------------------------------------------------------------- | | **300 Multiple Choices** | There are multiple options available for the resource the client can access. | | **301 Moved Permanently** | The requested resource has been permanently moved to a new URL. | | **302 Found** | The requested resource is temporarily located at a different URL. | | **304 Not Modified** | The resource has not been modified since the last request. | | **307 Temporary Redirect** | The requested resource is temporarily located at a different URL, and the client should retain the original request method. | ### **4xx (Client Errors)** | Code | Description | | ------------------------------------- | --------------------------------------------------------------------------------- | | **400 Bad Request** | The client's request is incorrect or badly formed. | | **401 Unauthorized** | The client is not authenticated. | | **403 Forbidden** | The client lacks permission to access the requested resource. | | **404 Not Found** | The requested resource could not be found on the server. | | **405 Method Not Allowed** | The request method is not allowed for the resource. | | **406 Not Acceptable** | The server cannot provide a response matching the list of acceptable media types. | | **407 Proxy Authentication Required** | The client must authenticate with a proxy. | | **408 Request Timeout** | The client's request has timed out. | | **409 Conflict** | There is a conflict with the current state of the resource. | | **429 Too Many Requests** | The client has exceeded the rate limits for requests. | ### **5xx (Server Errors)** | Code | Description | | --------------------------------------- | ------------------------------------------------------------------------------------------- | | **500 Internal Server Error** | An internal server error has occurred. | | **501 Not Implemented** | The server does not support the requested functionality. | | **502 Bad Gateway** | The server acts as a gateway and has received an invalid response from an upstream server. | | **503 Service Unavailable** | The server is temporarily unavailable, often due to overloading or maintenance. | | **504 Gateway Timeout** | The server acts as a gateway and did not receive a timely response from an upstream server. | | **505 HTTP Version Not Supported** | The server does not support the HTTP protocol version used in the request. | | **507 Insufficient Storage** | The server cannot create the resource due to insufficient storage space. | | **511 Network Authentication Required** | The client must authenticate to access the network or resource. | ## HTTP Methods HTTP (Hypertext Transfer Protocol) defines a set of request methods to indicate the desired action to be performed for a given resource. These methods play a crucial role in shaping the communication between clients and servers in web applications. Here's an overview of some commonly used HTTP methods. | Method | Descriptions | | ---------------- | ------------------------------------------------------------------------------------------------------------------------------------ | | **HTTP GET** | This retrieves a resource from the server. It is idempotent. Multiple identical requests return the same result. | | **HTTP PUT** | This updates or creates a resource. It is idempotent. Multiple identical requests will update the same resource. | | **HTTP POST** | This is used to create new resources. It is not idempotent, making two identical POST requests will duplicate the resource creation. | | **HTTP DELETE** | This is used to delete a resource. It is idempotent. Multiple identical requests will delete the same resource. | | **HTTP PATCH** | The PATCH method applies partial modifications to a resource. | | **HTTP HEAD** | The HEAD method asks for a response identical to a GET request but without the response body. | | **HTTP CONNECT** | The CONNECT method establishes a tunnel to the server identified by the target resource. | | **HTTP OPTIONS** | This describes the communication options for the target resource. | | **HTTP TRACE** | This performs a message loop-back test along the path to the target resource. | Use this cheat sheet to quickly reference and understand the meaning of HTTP error codes and methods. {% embed url="" %}