[Alex Vincent]

const notWhitespace = /\S/

function cleanWhitespace(node) {
  for (var x = 0; x < node.childNodes.length; x++) {
    var childNode = node.childNodes[x]
    if ((childNode.nodeType == 3)&&(!notWhitespace.test(childNode.nodeValue))) {
// that is, if it's a whitespace text node
      node.removeChild(node.childNodes[x])
      x--
    }
    if (childNode.nodeType == 1) {
// elements can have text child nodes of their own
      cleanWhitespace(childNode)
    }
  }
}

document.addEventListener("load", function() {
  cleanWhitespace(document)
}, true)

This script is intended to remove whitespace text nodes from a document. These nodes show up far more often than we want to admit, and leads to a DOM that is different in Mozilla than IE.

Make sure you use this only in documents where whitespace is expendable. XHTML documents are among these, as are MathML expressions and SVG images.

Theoretically, whitespace can be significant in some XML documents.