<div class="target" contenteditable="true">Paste your rtf from excel/somewhere else here and get the source of it (the console shows all available types).</div>

<script>

const target = document.querySelector('div.target');

​

target.addEventListener('paste', (event) => {

​

    console.log(event.clipboardData);

    console.log(event.clipboardData.types);

​

    let paste = (event.clipboardData || window.clipboardData).getData('text/rtf');

    console.log(paste);

    const selection = window.getSelection();

    if (!selection.rangeCount) return false;

    selection.deleteFromDocument();

    selection.getRangeAt(0).insertNode(document.createTextNode(paste));

    event.preventDefault();

});

</script>