Extremely simple to use. Simply go to the website and paste your code in, then click "find differences". It is easy to identify differences based on color coding, allows you to make comments about differences that exist, etc. It also allows some basic transformation such as converting to lowercase and trimming white space. They also have a desktop version you can download, but I have found that the online version is sufficient. Unless you are using it for constant, regular code promotion.

Simple comparison tool, works for text, json and my code files as well

Its so simple and direct to use You visit website, no ads nothing, just copy two text and voila, you receive difference between them. Once tried its image diff checker as well and that was also coool.