Detecting Browser Autofill

Question

How do you tell if a browser has auto filled a text-box? Especially with username & password boxes that autofill around page load.

My first question is when does

Answer 1

Here is CSS solution taken from Klarna UI team. See their nice implementation here resource

Works fine for me.

input:-webkit-autofill {
  animation-name: onAutoFillStart;
  transition: background-color 50000s ease-in-out 0s;
}
input:not(:-webkit-autofill) {
  animation-name: onAutoFillCancel;
}