# 400 Bad Request

The request is invalid, such as a missing or wrong field.

## What is **400 Bad Request**?

**400 Bad Request** means the request itself is wrong: invalid JSON, a missing field, a value out of range. The body should say what to fix.

Level: Apprentice · [More Web Development terms at this level](https://www.ask-codey.com/glossary/subjects/web-development/apprentice)

Updated: September 27, 2026

Source: https://www.ask-codey.com/glossary/400-bad-request