Compare text (diff checker)

Paste two versions of a document, config file, or code to highlight additions and removals.

🔒 Your files never leave your device

How it works

Uses the Myers diff algorithm (the same idea behind git diff) to find the smallest set of insertions and deletions. Line mode shows line numbers for both versions; word mode highlights changes inline, which is better for prose.

Limits: very large inputs with many differences can take a few seconds. Moved blocks are shown as a removal plus an addition.

Privacy: the tool runs in your browser, so nothing you add (files, text, passwords) is uploaded or stored by us. No account needed. It also works offline once loaded.