All HTTP Status Codes
400
Bad Request
4xx Client Error
RFC 9110What it means
The server cannot process the request because of a client error — malformed syntax, invalid request message framing, or deceptive request routing.
Common causes
- Malformed JSON or XML body
- Missing required parameters
- Invalid query string format
- Incorrect Content-Type header
- Request body too large
How to fix it
Check the request syntax, headers, and body. Validate JSON/XML before sending. Ensure required fields are present and correctly typed.
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