This is a better fiddler session comparer than everything I came across on the web. Most of the fiddler comparers do not do good job in comparing just what you need to compare. This comparer will divide the Heades, Body and URL Comparisons so you know exactly what is different and where. To install this comparer just copy The dll (OnFiddlerComparer.dll) from the release link above to your fiddler scripts folder
Most likely at C:\Users\aali\AppData\Local\Programs\Fiddler\Scripts
