Diff checker
Paste the original and the changed text to see every added and removed line.
How it works
The checker finds the longest common subsequence of lines between the two texts, the same idea behind diff and Git. Lines only in the original are marked as removed, lines only in the new text as added, and everything else is unchanged.
Turn on Ignore whitespace to skip differences in indentation and trailing spaces, useful when comparing reformatted code.
Private
Everything runs in your browser. Nothing you paste is uploaded, logged or stored on a server, so it's safe to use with private data.
Questions
Is the comparison line by line?
Yes. Changed lines show as one removed line and one added line, with the changed words highlighted.
Can I compare JSON?
Yes. For the clearest result, format both with the JSON formatter (with "Sort keys" on) first.