InputEvent.dataTransfer

var dataTransfer = inputEvent.dataTransfer

<p><span style="font-weight: bold; color: blue">Whoa, bold blue text!</span></p>
<p><span style="font-style: italic; color: red">Exciting: italic red text!</span></p>
<p>Boring normal text ;-(</p>

<hr>

<p contenteditable="true">Go on, try pasting some content into this editable paragraph and see what happens!</p>

<p class="result"></p>

var editable = document.querySelector('p[contenteditable]');
var result = document.querySelector('.result')
var dataTransferObj;

editable.addEventListener('input', (e) => {
  result.textContent = e.dataTransfer.getData('text/html');
});