Text Diff Checker
Paste two texts and see exactly what changed — line by line, instantly.
100% in your browser — files never leave your device
Paste text in both fields to see the diff.
Frequently asked questions
Is my text sent to a server?
No. The diff runs entirely in your browser using a longest-common-subsequence algorithm. Nothing you paste is uploaded anywhere.
What does "Ignore whitespace" do?
When enabled, leading/trailing whitespace is trimmed and runs of whitespace are collapsed to a single space before comparison. Lines that differ only in whitespace will be treated as equal.
How does the line number display work?
Left numbers track lines in the original text; right numbers track lines in the changed text. Removed lines show only a left number; added lines show only a right number; equal lines show both.