Text Diff Checker: How It Works and How to Use It
Compare two blocks of text and instantly see every word that was added, removed, or changed.
Like every tool on UltimateTools, it runs instantly in your browser, updates as you type, and doesn't require an account or sign-up to use.
What it calculates
Compare two texts and highlight every difference.
Whether you think of it as a "text diff checker" tool, a "compare text online or diff checker" tool, or simply the Text Diff Checker, this page covers the same calculation.
You can find it at any time on the Text Diff Checker page, where the calculator sits above a full explanation of the method it uses.
Tips for an accurate result
Read a sample paragraph out loud — it's often a faster gut check than any formula for whether writing flows well.
Don't over-optimize for a score at the expense of accuracy or nuance — a technically simpler sentence that's less precise isn't actually an improvement.
Shorter sentences and simpler words are the two levers that move most readability scores the most — start there if a score is low.
Re-check readability after editing, not just before — edits meant to simplify text sometimes accidentally make it more complex.
Related tools worth trying
If you found the Text Diff Checker useful, Reading Time Calculator, Readability Checker, Lorem Ipsum Generator cover closely related ground and are worth a look next.