- Add
autocomplete="off"
onto<form>
element; - Add hidden
<input>
withautocomplete="false"
as a first children element of the form.
<form autocomplete="off" method="post" action="">
<input autocomplete="false" name="hidden" type="text" style="display:none;">
...
This formation is going to prevent Chrome and Firefox to offer autofill and autocomplete for all input fields inside the form.
That one is closed as "Won't fix". Here's an issue that is still open: https://issues.chromium.org/issues/40910184