Local browser utility

Diff Checker

Paste two versions of a text to see a line-by-line difference with added and removed lines clearly highlighted.

Texts to comparePaste the original on the left and the changed version on the right.

Both texts are compared locally in your browser. We don't store or send your data anywhere.

Nothing compared yet

Comparison options

Added
0

Lines only in the changed text

Removed
0

Lines only in the original

Unchanged
0

Lines that match in both

Line-by-line comparison

Paste text into both boxes to see the comparison.

The comparison is line by line, not word by word. A line with one character changed shows as one removed line and one added line.

Questions About This Tool

Is this a character-by-character diff?

No. It is line-based, so an edited line becomes a removal plus an addition.

Why are large texts rejected?

The alignment algorithm requires work proportional to both line counts multiplied together. The limit prevents an unresponsive tab.

Can it ignore whitespace?

It can ignore leading and trailing whitespace. Whitespace inside a line remains significant.

Does it modify either input?

No. Comparison normalization creates internal keys; the visible input and displayed line text remain unchanged.