Diff Checker

A diff checker (or text compare tool) takes two pieces of text and shows you exactly what changed between them — which lines were added, which were removed, and which were edited. It is the same kind of comparison developers see in code reviews, but it works for any text: contracts, essays, configuration files, translations or notes. Paste your original text on the left and the changed version on the right and the differences are highlighted instantly.

Paste the first version into the "Original" box and the second into the "Changed" box. The comparison updates as you type: removed lines are shown in red, added lines in green, and edited lines show the changed words highlighted within the line. Use the Split view to see the two versions side by side, or the Unified view to read the changes inline like a Git diff.

Yes. Turn on "Ignore case" so that "Hello" and "hello" are treated as the same, and "Ignore whitespace" so that differences in indentation or leading and trailing spaces no longer count as a change. You can also choose whether edited lines are highlighted word by word or character by character, which is handy for spotting a single changed letter or a moved word.

Split view places the two texts in side-by-side columns, so you can read the original and the changed version in parallel — best on a wide screen. Unified view stacks everything in a single column with added and removed lines marked, the way Git and most code tools display a diff — best for long files or narrow screens. Both show the same information; pick whichever is easier to read.

Completely free with no sign-up or limits. The entire comparison runs in your browser with JavaScript, so the texts you paste are never uploaded to or stored on any server — you can safely diff confidential documents, contracts or source code, and the tool keeps working offline once the page has loaded.