HTTP Status Codes - Quick Recap
HTTP status codes tell the consumer of the API whether a specific HTTP request has been successfully processed or not.
A HTTP GET request is made to the JSONPlaceholder API to get all posts. The API returns all of the posts in the response along with a status code of 200 OK meaning that the request was successfully processed.
Why are status codes important?
It's important to return the correct status code. The API should not return a 200 OK status code for every request. The client will just assume that the request completed successfully which may not be the case. If some failure has happened on the API side then the appropriate status code should be returned (e.g. a 500 Internal Server Error).
There are 5 categories of HTTP status codes.
The most common status codes used are:
- 200 OK
- 201 Created
- 204 No Content
- 400 Bad Request
- 401 Unauthorized
- 404 Not Found
- 500 Internal Server Error
You can see a full list of HTTP status codes along with the details at Mozilla Developer Network - HTTP response status codes