type="text", autocomplete="off"

<input type="text" name="password" style="text-security:disc; -webkit-text-security:disc;" autocomplete="off"

使用font-family: 'dotsfont';

@font-face {
  font-family: 'dotsfont';
  src: url('dotsfont.eot');
  src: url('dotsfont.eot?#iefix') format('embedded-opentype'),
       url('dotsfont.woff') format('woff'),
       url('dotsfont.ttf') format('truetype'),
       url('dotsfont.svg#dotsfontregular') format('svg');
}

[conceal]:not(:active):not(:focus) {
  font-family: 'dotsfont';
}
<span conceal>hide me</span>