Text Diff Checker

A diff checker finds the smallest set of edits between two texts: what was deleted, what was added and what stayed the same. This tool uses the open-source jsdiff library, which implements the difference algorithm published by Eugene Myers in 1986, the same approach Git uses by default. The results are therefore very close to what you see on GitHub or in a code review. Red marks content removed from the original and green marks content added in the modified version.

Line diff works one whole line at a time, which suits code, configuration files, CSV data, bullet lists and contract clauses: any change inside a line highlights the entire line, so you can quickly scan which sections were touched. Character diff goes down to individual characters and is ideal for typos, punctuation, numbers or dates, for example when proofreading a translation, reviewing a press release or checking whether a price on a quote was altered. A good workflow is to locate changes with line diff first, then switch to character diff for the details.

Sometimes two texts that look identical are still flagged as different. The usual culprits are invisible characters: trailing spaces, tabs versus spaces, non-breaking spaces copied from Word or web pages, curly quotes, or different line endings, CRLF on Windows versus LF on macOS and Linux. If that happens, normalise both texts with our text cleaner first and compare again.

The comparison runs entirely in your browser and nothing is uploaded, so you can safely compare contracts, internal documents or unreleased code. Press "Load Demo" to see the difference between the two modes in a few seconds.