highlight all custom elements in dom

140bytes.js

[].forEach.call(document.all,function(e){-1!==e.constructor.name.indexOf("-")&&(e.style.border="3px solid red")});

bookmarklet.js

javascript:(function(){[].filter.call(document.all,function(el){return el.localName.indexOf('-')!=-1||el.getAttribute('is');}).forEach(function(el,i){el.style.border='3px solid red';});})();

real-custom-elements.js

[].forEach.call(document.all, function(el) {
  (el.localName.indexOf('-') != -1) && (el.constructor !== HTMLElement) && (el.style.border = '3px solid red');
});

source.js

// Highlights all custom elements on the page.
// To create a bookmarklet, use http://ted.mielczarek.org/code/mozilla/bookmarklet.html
[].filter.call(document.all, function(el) {
  return el.localName.indexOf('-') != -1 || el.getAttribute('is');
}).forEach(function(el, i) {
  el.style.border = '3px solid red';  
});