Find Over-Wide Elements :: What is pushing the page wider than the viewport, allowing that janky side scrolling?

find-overwide-elements.user.js

// ==UserScript==
// @name         Find Over-Wide Elements
// @namespace    https://gist.github.com/r-k-b/
// @version      1.0.0
// @description  What is pushing the page wider than the viewport, allowing that janky side scrolling?
// @author       Robert K. Bell
// @homepage     https://gist.github.com/r-k-b/83a411a2cf4be4de7cd0bb60321f66a7
// @downloadURL  https://gist.github.com/r-k-b/83a411a2cf4be4de7cd0bb60321f66a7/raw/find-overwide-elements.user.js
// @include      *://*/*
// @grant        none
// @run-at       context-menu
// ==/UserScript==

/* jshint esnext: true */

(() => {
  var docWidth = document.documentElement.offsetWidth;
  
  [].forEach.call(
    document.querySelectorAll('*'),
    function(el) {
      if (el.offsetWidth > docWidth) {
        console.log(el);
      }
    }
  );
});