Question 1

What are HTTP status codes?

Accepted Answer

HTTP status codes are standardized three-digit numbers returned by a web server in response to a client's request. They indicate the outcome of the request and help clients understand how to interpret the server's response.

Question 2

What's the difference between 4xx and 5xx error codes?

Accepted Answer

4xx status codes indicate client errors—problems with the request itself (like 404 Not Found or 400 Bad Request). 5xx status codes indicate server errors—problems on the server side (like 500 Internal Server Error or 503 Service Unavailable).

Question 3

When should I use a 201 instead of a 200 response?

Accepted Answer

Use 201 Created when a request successfully results in the creation of a new resource. Use 200 OK for successful requests that don't create new resources or when you want to include the created resource in the response body.

Question 4

What's the difference between 401 and 403 status codes?

Accepted Answer

401 Unauthorized means the client hasn't provided valid authentication credentials. 403 Forbidden means the client is authenticated but doesn't have permission to access the requested resource.

Question 5

Should I use 204 or 200 for successful DELETE requests?

Accepted Answer

For DELETE requests, 204 No Content is generally preferred if you don't need to return any content. Use 200 OK if you want to return information about the deletion in the response body.

Question 6

What's the purpose of 3xx redirect status codes?

Accepted Answer

3xx redirect status codes indicate that the client needs to perform a further action to complete the request. They're commonly used for URL redirects, caching directives, or indicating that a resource has moved.

Question 7

What does the 429 Too Many Requests status code mean?

Accepted Answer

429 Too Many Requests indicates that the user has sent too many requests in a given amount of time (rate limiting). It's used to protect APIs and services from abuse or overload.

Question 8

When should I use 502 Bad Gateway vs. 504 Gateway Timeout?

Accepted Answer

Use 502 Bad Gateway when your server (acting as a gateway/proxy) receives an invalid response from an upstream server. Use 504 Gateway Timeout when your server doesn't receive a response from the upstream server within the allowed time limit.

Question 9

What HTTP status code should I use for validation errors?

Accepted Answer

For validation errors, 400 Bad Request is typically appropriate. For more specific validation issues, you can also consider 422 Unprocessable Entity, which is specifically for semantically invalid requests.

Question 10

Are HTTP status codes case-sensitive?

Accepted Answer

The numeric codes themselves are just numbers, but the reason phrases (like 'Not Found' in 404 Not Found) are case-sensitive according to the HTTP specification, though many implementations treat them case-insensitively in practice.

HTTP Status Code Reference

HTTP Status Codes

1xx Informational

2xx Success

3xx Redirection

4xx Client Error

5xx Server Error

Select a Status Code

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