4xx Client Error
HTTP 431 Request Header Fields Too Large
The request headers are too large for the server.
Check a URL's HTTP statusWhat 431 means
Usually caused by oversized cookies accumulating on a domain.
Common causes
- Too many or very large cookies.
- A long Referer or custom header.
How to fix it
- Clear cookies for the site.
- Reduce cookie size on the server side.
How to check a status code
Enter a URL in the HTTP Status Checker to see its status code, every redirect hop, and response time. For redirect-heavy pages, the Website Speed Test shows how much time redirects add.
FAQ
- What does HTTP 431 mean?
- 431 Request Header Fields Too Large is a 4xx client error status code. The request headers are too large for the server.
- What causes a 431 error?
- Too many or very large cookies. A long Referer or custom header.
- How do I fix HTTP 431?
- Clear cookies for the site. Reduce cookie size on the server side.
Defined in RFC 6585.
Other 4xx client error codes
400 Bad Request401 Unauthorized403 Forbidden404 Not Found405 Method Not Allowed406 Not Acceptable408 Request Timeout409 Conflict410 Gone413 Content Too Large414 URI Too Long415 Unsupported Media Type418 I'm a teapot422 Unprocessable Content425 Too Early429 Too Many Requests451 Unavailable For Legal Reasons