Text Diff Compare
A text diff tool compares two versions of text and highlights which lines were added, removed, or stayed the same — the same line-level comparison behind tools like `git diff`. The longest common subsequence algorithm is the same core technique behind git diff and most version-control tools, which is why lines that only moved position, rather than actually changing, can still show up as one removal and one addition instead of being recognized as unchanged.
How it works
- Paste the original text on the left and the changed text on the right.
- Read the combined result: unchanged lines are plain, removed lines are marked "-", added lines are marked "+".
- Use the added/removed counts above the result for a quick summary.
Formula Longest common subsequence (LCS) over lines, then backtracked into same/added/removed rows
Frequently asked questions
Does this compare word by word or line by line?
Line by line. A single-character edit on a long line will still show that whole line as one removal plus one addition.
Does line order matter?
Yes — moving a block of lines shows as a removal at the old position and an addition at the new one, the same way `git diff` reports a move.
Is whitespace-only difference detected?
Yes — trailing spaces or different indentation make two otherwise-identical lines count as different.
Is this the same algorithm as git diff?
The same family — both are longest-common-subsequence based line diffs, though git additionally supports word-level and rename detection.
Is my text uploaded anywhere?
No. Comparison runs entirely in your browser.