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

Ugh, the 431 error is the worst! I had this issue last week and it drove me nuts.

Turns out, my browser extensions were adding a ton of headers. Disabled a few sketchy ones and boom—fixed.

Also, check out Chrome's "EditThisCookie" extension. Helps you see and delete cookies causing the issue. Lifesaver!