index.md

---

title: 400 Bad Request
slug: Web/HTTP/Status/400
spec-urls: https://httpwg.org/specs/rfc9110.html#status.400

---

{{HTTPSidebar}}

The HyperText Transfer Protocol (HTTP) 400 Bad Request response status code indicates that the server cannot or will not process the request due to something that is perceived to be a client error (for example, malformed request syntax, invalid request message framing, or deceptive request routing).

Warning: The client should not repeat this request without modification.

Status

400 Bad Request

Specifications

{{Specifications}}

See also

• HTTP Status Code Definitions