Find those pesky unintended body overflow

find_overflow_elements_on_page.js

var doc_width = document.documentElement.offsetWidth;

[].forEach.call(
  document.querySelectorAll("*"),
  function(pesky_el) {
    if(pesky_el.offsetWidth > doc_width) {
      console.log(pesky_el);
    }
  }
);