Text Diff Checker

A diff checker compares two versions of some text and shows the differences between them. Writers use it to see an editor's changes, lawyers to compare contract drafts, students to check revisions, and developers to compare configuration files or code outside version control.

This checker compares by line, word or character, can ignore case and whitespace, and shows a combined view with additions and deletions marked, plus a count of what was added and removed. Nothing is uploaded, so confidential drafts stay on your device.

The diff uses the jsdiff library's implementation of Myers' algorithm, the same approach Git uses, which finds the smallest set of insertions and deletions that turns one text into the other.

Line mode suits code and lists, where whole lines move; word mode suits contracts, essays and copy edits; character mode catches one-letter typos. Changes are marked with underline and strike-through as well as colour, so they're clear without relying on colour alone.