The data read-only property of the InputEvent interface returns a string with inserted characters. This may be an empty string if the change doesn't insert text, such as when characters are deleted.

A string.

In the following example, an event listener receives the input event. Any textual change to the <input> element is retrieved by InputEvent.data and inserted into a paragraph using the Node.textContent property.

<p>Some text to copy and paste.</p>

<input type="text" />

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

const editable = document.querySelector("input");
const result = document.querySelector(".result");

editable.addEventListener("input", (e) => {
  result.textContent = `Inputted text: ${e.data}`;
});