Getting a 431 Error - Request Header Fields Too Large. How to Fix It? or What Causes a 431 Error and

Ugh, 431 errors are such a pain.

If you're on Apache, tweak `LimitRequestFieldSize` in httpd.conf. Default is like 8KB—way too small.

Also, check out "Postman" for testing APIs. Helps spot header issues before they break stuff.