Often times we just need to quickly compare differences between documents or web pages without the hassle of copy/pasting in Word and using the traditional Compare feature.
Diff Checker is a great tool, which allows you to quickly paste the original and changed text, and get results in seconds in a visually appealing fashion, certainly more intuitive than the window jigsaw puzzle MS Word has currently on offer.
The tool also claims to check differences in PDF and images files. I’ve tested the PDF comparison but the results were not great, owing to many (incomprehensible) false positives. If you wish to compare PDFs, you’re better off with the built-in Compare feature in Acrobat DC. For comparisons of simple text, however, Diff Checker is totally worth it.
By default, Diff Checker doesn’t store the differences on the server (you can do so by creating a free account), but, as usual, I’d err on the side of caution before comparing documents with sensitive content. Be sure to read the fine print.