See https://greasyfork.org/forum/discussion/449/gsmarena-com-a-script-to-highlight-rows-with-differences-when-comparing-phones
// ==UserScript==
// @name GSMArena Highlight Compare Differences
// @author Jefferson "jscher2000" Scher
// @namespace JeffersonScher
// @description See https://greasyfork.org/forum/discussion/449/gsmarena-com-a-script-to-highlight-rows-with-differences-when-comparing-phones
// @license BSD 3-clause
// @include http://www.gsmarena.com/compare.php3*
// @version 0.1.1
// @grant none
// ==/UserScript==
// Only run if a second phone was selected (check for presence of nfo2 entries)
var test = document.getElementsByClassName("nfo2");
if (test.length > 0){
// Add rules to style rows designated as having differences
var s = document.createElement("style");
s.setAttribute("type", "text/css");
s.appendChild(document.createTextNode(".hcdiff .ttl, .hcdiff .nfo, .hcdiff .nfo2{background:#ffb !important; box-shadow:inset 0 0 .45em #ee0 !important;}"));
document.body.appendChild(s);
// Check all rows under #specs-list (there are numerous tables in here)
var rows = document.querySelectorAll("#specs-list tr");
for (var i=0; i<rows.length; i++){
if (rows[i].children.length > 1){
// Compare the last cell in the row to the send-to-last (needed because numbers of cells can vary)
if (rows[i].lastElementChild.innerHTML != rows[i].lastElementChild.previousElementSibling.innerHTML){
rows[i].className = "hcdiff";
}
}
}
}