A couple of years ago I made a simple HTML page which I could use as a tool to find differences in lists. This I used to compare output of different systems, queries or other sort of lists. I decided to share the tool which can be found here:
Tool for comparing lists to find differences and similarities
The tool is all client-side which means the data put into it is not sent anywhere (I do not want your data). It can handle casing and white-space and output lists ready to be copied.
You can see an image of the tool here:
That is all
I hope you enjoy this tool, please let me know in the comments if you do!