Paste two versions and see what changed.
The diff compares line by line and highlights what was removed from the first version and added in the second, so edits are easy to spot.
Nothing is uploaded — both versions stay in your browser.
More tools
It compares the two texts line by line, marks lines only in the first version as removed, lines only in the second as added, and leaves unchanged lines plain.
Either. It works on any text, since it compares whole lines — handy for spotting changes between two drafts or two config files.