HTTP response status codes | REST API response codes | @ConceptandCoding

Summary

In this 10-minute series episode, the host delves into HTTP response codes, highlighting the top 10. The codes are categorized into five groups: 1xx informational, indicating the server's readiness to proceed; 2xx success, with 200 for GET requests, 201 for successful POST requests creating new records, 202 for accepted requests pending processing, and 204 for DELETE operations with no content to return; 3xx redirects, like 301 for permanent URL changes; 4xx client errors, such as 400 for bad requests due to missing data and 404 for non-existent resources; and 5xx server errors, like 500 for internal server issues. The discussion provides clarity on how these codes are used in web communications.

Takeaways

• 📝 Response codes are divided into five categories: 1xx (Informational), 2xx (Success), 3xx (Redirection), 4xx (Client Error), and 5xx (Server Error).
• 🔄 1xx codes are informational responses, indicating that the server is ready to communicate with the client but has not yet completed the request.
• ✅ 100 (Continue) status code is used when a server checks the request's headers and decides it can handle the request before the client sends the body.
• 🎯 2xx codes indicate that the client's request was successfully received, understood, and accepted by the server.
• 👍 200 (OK) is the standard response for successful HTTP requests, typically used with GET requests, and implies that the response body contains the requested data.
• 🆕 201 (Created) is used with POST requests to indicate that the request has been fulfilled and has resulted in the creation of a new resource.
• 🗂️ 202 (Accepted) means that the request has been accepted for processing, but the processing is not complete, and the client can check back later for the result.
• ❌ 204 (No Content) is used when a request is successfully processed, but there is no content to return in the response body, such as after a DELETE operation.
• 🔄 3xx codes are for redirection, where the client must take additional action to complete the request, such as moving to a new URI.
• 🔄 301 (Moved Permanently) is used to redirect clients to a new URI when an API endpoint has been permanently changed or deprecated.
• 🚫 4xx codes represent client errors, indicating that the client's request contains bad syntax or cannot be fulfilled.
• 🚨 400 (Bad Request) is sent when the server cannot process the request due to invalid syntax or missing required data.
• 🔍 404 (Not Found) indicates that the requested resource is not available on the server, and the client should not retry the request.
• 🛑 422 (Unprocessable Entity) is used when the server understands the content type of the request entity and the syntax of the request is correct, but the request was unable to be followed due to semantic errors.
• ⚠️ 5xx codes are server errors, indicating that the server has failed to fulfill an apparently valid request.
• 💡 500 (Internal Server Error) is a generic error message, given when an unexpected condition was encountered and no more specific message is suitable.

Q & A

What are the three parts that generally make up a response?

A response generally contains three parts: status code, header, and body.

How many categories are status codes divided into and what are they?

Status codes are divided into five categories: 1xx (Informational), 2xx (Success), 3xx (Redirection), 4xx (Client Error), and 5xx (Server Error).

What does the 1xx category of status codes indicate?

The 1xx category of status codes is known as informational, indicating that the server is sending an interim response to the client, signaling that the client can proceed further.

What is the meaning of the 100 status code?

The 100 status code stands for 'Continue' and is used when a server has received a request with an 'Expect: 100-continue' header and the server is ready to accept the request.

Which status code is commonly seen during GET requests and what does it represent?

The 200 status code is commonly seen during GET requests and represents 'OK', indicating that the request has succeeded and the response body contains the requested data.

What does the 201 status code signify and in which type of APIs is it typically used?

The 201 status code signifies that the request has been fulfilled and results in a new resource being created, typically used in POST APIs.

What is the purpose of the 202 status code and in what scenario is it commonly used?

The 202 status code indicates that the request has been accepted for processing but the processing has not been completed, commonly used in scenarios like export APIs where the server has accepted the request but the response is not yet available.

Why is the 204 status code often used with DELETE requests?

The 204 status code is used with DELETE requests because it indicates 'No Content', meaning that the server successfully processed the request, but is not returning any content.

What does the 3xx category of status codes represent and how is it typically used?

The 3xx category of status codes represents redirection, indicating that further action needs to be taken by the client to fulfill the request, typically used when migrating from old APIs to new ones.

What is the significance of the 301 status code and how does it affect the client?

The 301 status code signifies 'Moved Permanently', instructing the client to redirect to a new URI provided in the header, typically used when an API is deprecated and clients need to use a new API endpoint.

What does the 4xx category of status codes indicate and what is an example of a 4xx status code?

The 4xx category of status codes indicates client errors, such as 400 Bad Request, which signifies that the request cannot be processed due to incorrect syntax or missing required data.

What is the 422 status code and under what circumstances is it used?

The 422 status code stands for 'Unprocessable Entity' and is used when the server understands the content type of the request entity and the syntax of the request entity is correct, but it was unable to process the contained instructions.

What does the 5xx category of status codes represent and what is an example of a 5xx status code?

The 5xx category of status codes represents server errors, such as 500 Internal Server Error, indicating that the server encountered an unexpected condition that prevented it from fulfilling the request.