Using 'diff' (or anything else) to get character-level diff between text files

Question

I\'d like to use \'diff\' to get a both line difference between and character difference. For example, consider:

File 1

abcde
ab         


        

Answer 1

Here is an online text comparison tool: http://text-compare.com/

It can highlight every single char that is different and continues compare the rest.