Text Diff Viewer

Comparing two versions of a document by eye is slow and unreliable — a single swapped word or missing sentence buried in a wall of text is easy to miss. The Text Diff Checker solves this by comparing two blocks of text and instantly highlighting every addition, deletion, and change between them, so you can spot exactly what was edited without reading both versions line by line. It's built for anyone who needs to verify what changed — writers checking a revised draft, developers comparing config files or commit messages, translators checking edits, or students comparing essay drafts.

Paste your original text into one panel and the revised text into the other, and the tool renders a side-by-side comparison with additions and deletions color-coded so changes stand out immediately. It supports both line-by-line comparison, useful for spotting which whole lines were added, removed, or reordered, and word-by-word comparison, which pinpoints the exact words that changed within a line rather than just flagging the whole line as different. This dual-mode approach means you can catch both structural edits (a paragraph moved or deleted) and small wording tweaks (a single word swapped) in the same pass.

Because everything runs client-side in your browser, neither the original nor the revised text is uploaded anywhere — useful when comparing drafts of contracts, private notes, or unreleased code that you don't want leaving your machine. A common workflow is pasting an old and new version of a paragraph to confirm an editor's changes match what was agreed, or diffing two versions of a config file before merging to make sure nothing unexpected slipped in.