See exactly what changed between two texts.

Paste two versions of a text and see every word, character or line that was added or taken out, side by side or in one, counted, in your browser.

By Suraj Kumar1 November 20263 min read

A text box with a line under it that says 1,204 words, about 5 minutes to read, beside cards for counting, capitals, comparing and tidying.

A contract came back “with a few small changes”. A teacher wants to see what a student rewrote. A list was edited and nobody remembers how. Comparing two texts by eye misses things; the diff checker marks every change and counts them.

Paste both, and read the changes.

Paste the first version and the second. The page says how many words were added and taken out, and shows the texts side by side, or in one column, with what was added underlined and what was taken out struck through. The changes are found by jsdiff with Myers' method, which finds the fewest changes that turn one text into the other, as git does.

By words, characters, lines or sentences.

Words suit writing; characters suit codes, names and numbers, where one letter matters; lines suit lists and code, and count as git diff counts (the tests check them against git diff --numstat). Switches let differences in capitals or in spaces and line breaks pass.

Large texts.

Texts of more than 200 KB are compared in the background on your own device, so the page keeps answering. When two texts differ in so many places that comparing them word by word takes too long, they are compared line by line instead, which is quicker, and the page says so.

Nothing leaves your browser.

Everything is worked out on your device: what you paste, type or open is never sent anywhere, and nothing is kept when you leave the page. There are no adverts, no accounts and no limits on length.

Read what the site keeps

A little less theory. A little more doing.

Try it on your own terms, with a free browser tool.

Try the tool