Text Diff
Paste the original text in the left field and the modified version in the right. Differences appear immediately — green lines were added, red lines were removed.
Common questions
What algorithm is used for comparison?
The tool uses the Longest Common Subsequence (LCS) algorithm — the same one used by the classic Unix diff utility. LCS finds the longest common subsequence between two texts and derives the minimum set of changes needed to transform one into the other.
Does the tool support character-level diff?
No — comparison is line-by-line. The output shows which lines were added, removed, or unchanged. For most use cases (code, configuration, prose) a line diff is more readable than a character diff, which tends to produce noisy output for small edits in long lines.
Is my text sent to the server?
No. The entire diff algorithm runs in your browser. Nothing you type is transmitted over the network.