Can I escape html special chars in javascript?

function escapeHtml(html){
  var text = document.createTextNode(html);
  var p = document.createElement('p');
  p.appendChild(text);
  return p.innerHTML;
}

// Escape while typing & print result
document.querySelector('input').addEventListener('input', e => {
  console.clear();
  console.log( escapeHtml(e.target.value) );
});

<input style='width:90%; padding:6px;' placeholder='&lt;b&gt;cool&lt;/b&gt;'>

You can use jQuery's .text() function.

For example:

http://jsfiddle.net/9H6Ch/

From the jQuery documentation regarding the .text() function:

We need to be aware that this method escapes the string provided as necessary so that it will render correctly in HTML. To do so, it calls the DOM method .createTextNode(), does not interpret the string as HTML.

Previous Versions of the jQuery Documentation worded it this way (emphasis added):

We need to be aware that this method escapes the string provided as necessary so that it will render correctly in HTML. To do so, it calls the DOM method .createTextNode(), which replaces special characters with their HTML entity equivalents (such as &amplt; for <).

Here's a solution that will work in practically every web browser:

function escapeHtml(unsafe)
{
    return unsafe
         .replace(/&/g, "&")
         .replace(/</g, "&lt;")
         .replace(/>/g, "&gt;")
         .replace(/"/g, "&quot;")
         .replace(/'/g, "&#039;");
 }

If you only support modern web browsers (2020+), then you can use the new replaceAll function:

const escapeHtml = (unsafe) => {
    return unsafe.replaceAll('&', '&amp;').replaceAll('<', '&lt;').replaceAll('>', '&gt;').replaceAll('"', '&quot;').replaceAll("'", '&#039;');
}