Text Diff Tool
Compare two blocks of text and see the differences highlighted line by line
How to Use
Paste the original text on the left and the modified text on the right, then click Compare. Lines that were added appear in green, lines removed appear in red, and unchanged lines are dimmed for context. Changed words within a line are highlighted inline for precision.
What This Tool Does
This diff tool uses a longest common subsequence (LCS) algorithm to compute the minimal set of changes between two texts. It supports unified and side-by-side views, highlights intra-line word differences, and provides statistics on additions, deletions and unchanged lines.
Is My Data Safe?
Yes. The comparison runs entirely in your browser with JavaScript. Your text is never sent to any server. There's no backend, no API call, no logging. You can verify this by opening your browser's network tab.
When to Use a Diff Tool
Diff tools are essential for reviewing code changes, comparing configuration files, checking document revisions, verifying data migrations, and debugging unexpected output changes. They help you quickly spot what changed, what was added, and what was removed.