Diff bookmarklet

diff-content-versions.js

var $ = jQuery;

$.ajax({
  url: $('link[rel="latest-version"').prop('href')
}).done(function(data){
  var fullPageHTML = $.parseHTML(data);
  var $contentB = $(fullPageHTML).find('.lex-region-content article');
  $contentB.find('.workbench-moderation-entity-moderation-form').hide();

  html2canvas($('.lex-region-content article'), {
    onrendered: function(canvas) {
      var image1, image2;
      $('.lex-region-content article').html($contentB.html());
      image1 = canvas;
      html2canvas($('.lex-region-content article'), {
        onrendered: function(canvas) {
          image2 = canvas;
          c = imagediff.diff(image1, image2);
          var resultCanvas = imagediff.createCanvas();
          resultCanvas.width = image1.width;
          resultCanvas.height = image1.height;
          context = resultCanvas.getContext('2d');
          context.putImageData(c, 0, 0);
          $('.lex-region-content article').prepend(resultCanvas);
        }
      });
    }
  });
});

index.html

<a href="javascript:void(function () {
var jsCode = document.createElement('script');
jsCode.setAttribute('src', 'https://gist.githubusercontent.com/eeeschwartz/fcb697eef4dd96a6f6ae138d8b9d20af/raw/diff-content-versions.js');
document.body.appendChild(jsCode);
}())">View differences</a>