Text Diff
Paste two versions of a text to see which lines were added or removed. Computed locally.
How it works
Paste the original on the left and the changed version on the right, then press Compare. Removed lines are marked with - and a red background, added lines with + and green.
The comparison uses a longest-common-subsequence algorithm, the same idea behind diff and Git, so moved blocks show up as a removal plus an addition. For JSON, run both sides through the formatter with sorted keys first for a cleaner result.
Questions
Is there a size limit?
Very large inputs (tens of thousands of lines on both sides) are refused to keep your browser responsive.
Does it compare words within a line?
Not yet. It compares whole lines; changed lines appear as one removal and one addition.