What is '400 Bad Request'? Learn how to use and/or fix this HTTP status code, with free examples and code snippets. The 4xx family of status codes is the one we’re investigating here as they relate to invalid or corrupt requests from the client. Specifically, we’ll take a closer look at the 400 Bad Request error: what this error means, what causes it as well as some specific steps to fix the issue. Encountering HTTP errors like 400, 403, 404, 500, 502, or 503 can be frustrating, but fear not! In this comprehensive tutorial, we’ll explain what these errors mean and provide step-by-step solutions to fix them. The HTTP specification intends this status code to be used for "limited-time, promotional services". APIs should not feel compelled to indicate resources that have been deleted with this status code.