Paste your original text in the left editor and the changed version in the right editor. Both use Monaco — the same editor that powers VS Code — so you get syntax highlighting, line numbers, and a minimap out of the box.
The tool runs Myers' diff algorithm on the two texts and computes exactly which lines were added, removed, or left unchanged. A stats bar shows the totals before you even scroll.
The result shows two read-only editors side by side. Removed lines are highlighted red in the Original (left). Added lines are highlighted green in the Changed (right). Both editors scroll in sync so corresponding content always stays aligned.
Click "← Edit" to return to the input view with your texts intact. Adjust the options, fix a typo, or paste an entirely new document, then click Compare again.
This tool uses Myers' algorithm (1986) — the same algorithm Git uses for `git diff`. It finds the shortest edit script: the minimum number of line insertions and deletions needed to transform the original document into the changed one. "Shortest" means the diff is as concise as possible, grouping related changes together and avoiding spurious matches that would make the output harder to read.