HTML

blink html

<!-- HTML -->
<!-- Using blink is not recommended. If you want to try it for fun... -->
<span id="blinker">Blinking!</span>

// JavaScript
setInterval( () => { 
  const blinker = document.getElementById('blinker')
  blinker.style.visibility = (blinker.style.visibility == 'hidden' ? ''
: 'hidden')}, 500);