HTTP 400 Bad Request — What It Means & How to Fix It
Error4xx client error
Overview
The HTTP 400 Bad Request status code indicates the server cannot process the request due to a client-side error such as malformed syntax, invalid parameters, or missing required fields.
Key Details
- This is a generic client error response when the request is malformed or invalid.
- The server should include details about what was wrong with the request.
- Common in API calls where the request body does not match the expected format.
- It indicates the client should not repeat the request without modifications.
- Form validation errors on the server side often result in this status.
Common Causes
- Malformed JSON or XML in the request body.
- Missing required parameters or headers.
- Invalid data types or values that fail server-side validation.
- URL encoding errors or special characters not properly escaped.
Steps
- 1Review the response body for specific error details about what is invalid.
- 2Validate your request body against the API documentation.
- 3Check for proper content-type headers matching your request body format.
- 4Ensure all required fields are present and have valid values.
- 5Use developer tools to inspect the exact request being sent.
Tags
httpclient-errorbad-requestvalidation
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ErrorFrequently Asked Questions
It means the server could not understand or process the request due to invalid syntax, missing parameters, or other client-side errors in the request.