How the comparison works
The tool finds the longest common subsequence of lines between the two texts, then marks lines that exist only in the original as removed (red) and lines that exist only in the changed text as added (green). Unchanged lines are shown in grey.
Limits
- The comparison is by whole lines: changing one word marks the entire line as changed.
- Very large inputs (over about 2,000 lines each) are refused to keep your browser responsive.
- Whitespace differences count as changes.
Privacy
Both texts stay in your browser. Nothing is uploaded or stored.