Text Diff Checker
Compare two texts and highlight differences
Reading the comparison
Lines prefixed − exist only in the original; lines prefixed + exist only in the changed version. Unmarked lines are identical in both. A line that was edited shows up as a removal immediately followed by an addition, since the comparison works line by line.
How the diff is computed
The comparison uses a longest-common-subsequence algorithm — the same approach behind git diff. It finds the largest set of lines that appear in both texts in the same order, then reports everything else as an addition or a removal. That gives a minimal, stable diff rather than flagging everything after the first change.
Useful for checking what changed between two drafts, two config files, or two versions of a copied-and-pasted list. Both texts stay in your browser.