Text Diff Checker

It compares the two texts line by line using Myers' diff algorithm, the same approach used by Git, to find the smallest set of added and removed lines. Inside lines that were modified it runs a second word-level comparison so only the words that changed are highlighted.

Side-by-side view shows the original on the left and the changed text on the right, which is easy to scan. Unified view shows a single column where removed lines start with a minus sign and added lines start with a plus sign, like the output of git diff.

Ignore whitespace treats runs of spaces and tabs as a single space and ignores spaces at the start and end of a line, so re-indented code does not show as changed. Ignore case treats uppercase and lowercase letters as equal. Both options apply to the line comparison and to the word highlights.

Yes. Each side can have up to 10,000 lines and the two texts together can be up to 2,000,000 characters. If you go over, the tool tells you instead of freezing your browser. For larger files, compare them in sections. If two very large texts are almost completely different, parts of the result may be shown as whole-block replacements.

A final line break creates an extra empty line at the end of the text, so a text that ends with a newline differs from one that does not. If you do not care about this, remove the trailing newline from either side before comparing.

No. The comparison runs entirely in your browser. Your text is not sent to a server or saved, so it is safe to compare private notes, contracts and source code.