Text Diff Checker
Compare two blocks of text locally with line-level additions and removals plus optional whitespace and case normalization.
Compare text locally with a shortest-edit-script style line diff. Each side is limited to 1 MB / 5,000 lines to prevent browser lockups.
Ready to compare.
How the comparison works
The comparison uses a Myers-style shortest edit script at line level. Unchanged lines begin with a space, deleted lines with -, and inserted lines with +.
Normalization options
Whitespace and case can be ignored for matching only; the displayed lines remain the original text so review remains auditable.
Privacy
Both texts remain in the browser. The tool does not upload, save or log them.