About this text diff tool
Paste the two versions into the left and right boxes and hit Compare for a line-by-line diff. The tool uses longest-common-subsequence dynamic programming to identify inserted, deleted and unchanged lines, highlighting additions in green and deletions in red, with added/removed/unchanged counts shown above.
To keep the page responsive, each side is limited to 1500 lines and you will get a clear notice beyond that. The whole comparison runs locally in your browser and nothing is uploaded — great for reviewing contract edits, code changes or copy revisions.