A text diff highlights exactly what changed between two versions of a document — lines added, removed, or left untouched — the same underlying idea behind git diff, code review tools, and document version history.
Paste the original text on the left and the changed version on the right, then compare. Added lines are highlighted in green, removed lines in red, and unchanged lines are shown as-is for context.
Comparison runs entirely in your browser using the diff (jsdiff) library — nothing you paste is sent anywhere.
What kind of diff algorithm does this use?
It uses the same Myers diff algorithm family as git diff and most text-diffing tools (via the diff / jsdiff library), comparing line by line to find the minimal set of changes.
Can I diff JSON or code, not just plain text?
Yes — the comparison is purely line-based text, so it works for JSON, code, config files, or any plain text; for JSON specifically, format both sides consistently first (see the JSON Formatter) so differences reflect content, not just whitespace.
Does the diff ignore whitespace differences?
No — by default whitespace changes are shown like any other difference, since a trailing space or changed indentation is often meaningful in code.