HTTP 414 URI Too Long vs 431 Request Header Fields Too Large
Both HTTP 414 (URI Too Long) and 431 (Request Header Fields Too Large) belong to the 4xx Client Error category. 414 indicates that the URI provided was too long for the server to process. Meanwhile, 431 means that the server refuses to process the request because an individual header field or all headers collectively are too large.
Description
The URI provided was too long for the server to process.
When You See It
When query strings are extremely long or when accidentally sending a request body in the URL.
How to Fix
Shorten the URL. Move long parameters to the request body using POST instead of GET.
Description
The server refuses to process the request because an individual header field or all headers collectively are too large.
When You See It
When cookies accumulate to an excessive size, or a single header (like Authorization) is too long.
How to Fix
Reduce header sizes. Clear excessive cookies. Use shorter tokens.
Key Differences
HTTP 414: The URI provided was too long for the server to process.
HTTP 431: The server refuses to process the request because an individual header field or all headers collectively are too large.
You encounter 414 when when query strings are extremely long or when accidentally sending a request body in the URL.
You encounter 431 when when cookies accumulate to an excessive size, or a single header (like Authorization) is too long.
When to Use Which
For 414 (URI Too Long): Shorten the URL. Move long parameters to the request body using POST instead of GET. For 431 (Request Header Fields Too Large): Reduce header sizes. Clear excessive cookies. Use shorter tokens.