How to use
- Paste the original text into the left box and the new text into the right box.
- Choose line mode, or word mode to highlight the exact words that changed.
- Tick “Ignore whitespace” if spaces and tabs should not count as changes.
- Click Compare. Green rows were added, red rows removed, yellow rows changed.
A diff checker shows exactly what changed between two versions of a text: a contract draft and its revision, two config files, a translated string table, or code copied from different places. Paste the old version on the left and the new one on the right, and the tool lines them up side by side with line numbers while both panes scroll together.
Lines are aligned with the Myers algorithm from the jsdiff 5.2.0 library, the same algorithm behind the default mode of git diff. When a block of deleted lines is directly followed by added lines, they are paired one to one and marked as changed; leftover lines appear as plain additions or deletions. Word mode also highlights the differing words inside changed lines. “Ignore whitespace” removes every space and tab before comparing, so lines that differ only in spacing count as equal.
A few limits: text is split on line feeds, so if one version uses Windows line endings (CRLF) and the other does not, every line can show as changed unless whitespace is ignored. Long lines do not wrap; scroll sideways to read them. The comparison runs entirely in your browser, so confidential documents stay on your device.