4xx Client errors
400 Bad Request
The server couldn't understand the request.
Common causes
- Malformed JSON or form data.
- Missing or invalid parameters.
- A cookie or header too big or corrupted.
How to fix it
- Check the request body and parameters against the API's documentation.
- As a visitor: clear the site's cookies and try again.
Find out the moment your site returns 400
Spot Downtime monitors count this as down and alert you, since visitors see an error. (The public “Is it down?” checker treats 4xx answers from big sites as online, because many refuse automated requests.)