When you compare code using Beyond Compare and see a big red block of difference, many times the difference is actually just of tabs or space. It can be set as not-important text and then Beyond Compare can hide these differences.
Here is how you can ignore the leading and trailing whitespace:
Beyond Compare 3
Start with comparing two file. In the window that comes up, go to Session menu, and click Session Settings. Switch to Importance tab, and there you go! Things are a bit differently organized, but it’s here.
Important Note: Do not forget to change the value of the bottom dropdown to “Also update session defaults”.
Beyond Compare 2
Go to Tools > Options > Rules. Select “Everything Else ” at the bottom. Click Edit. Go to Importance tab and check Leading Whitespace and Trailing Whitespace. Finally, close all boxes. That”s it!
Here I have assumed that you are comparing aspx or .vb/.cs files. If you are comparing file types which are defined in Beyond Compare, you need to select the appropriate rule instead of everything else.