Text Diff Checker
Compare two texts and see added and removed lines.
Your line-by-line diff appears here
Paste an original and a changed version, then click Compare. Removed lines show in red, added lines in green — computed in your browser with nothing sent to a server.
Runs entirely in your browserCompare two texts line by line, locally
A diff shows exactly what changed between two versions of a text: which lines were added and which were removed. Paste the original on the left and the changed version on the right, and this tool aligns the two using a longest-common-subsequence algorithm — the same idea behind git diffs — so unchanged lines line up and only the real edits stand out. Removed lines are marked in red, added lines in green. All comparison happens in your browser and neither text is uploaded to any server.
Common questions
How does the diff work?
The tool splits both texts into lines and computes the longest common subsequence of lines. Lines only in the original are shown as removed, lines only in the changed version are shown as added, and shared lines are shown as unchanged context.
Is this a character-level or line-level diff?
It is a line-level diff. Each line is compared as a whole unit, which is the most useful view for code, config, and prose. A single edit inside a line appears as that line removed and the new version added.
What do the colours mean?
Green lines with a plus were added in the changed text. Red lines with a minus were removed from the original. Lines with no marker are unchanged and shown for context.
Does whitespace matter?
Yes. Lines are compared exactly, including leading and trailing spaces, so two lines that differ only in whitespace are treated as different. Trim your text first if you want to ignore that.
Are my texts uploaded anywhere?
No. Both texts are compared entirely in your browser with JavaScript. Nothing you paste is uploaded or stored on a server.