Compare two texts side by side and highlight the differences line by line. Free online diff checker that runs entirely in your browser.
Paste your original text on one side and the changed text on the other. The tool lines them up and highlights the differences line by line, so additions, removals and edits are easy to spot. It works for anything text-based — code snippets, config files, documents, log lines or copy.
Because the comparison updates as you edit, you can paste two versions and immediately see exactly what changed between them.
Figuring out what changed between two versions of something by reading both in full is slow and easy to get wrong. A diff shows only the differences, which is how you quickly review an edit, confirm a config change, or check that a copied block matches the original.
It is useful well beyond code — proofreading two drafts, comparing two API responses, or spotting an unexpected change in a settings file.
The tool runs a line-by-line diff algorithm in your browser, comparing the two inputs and marking each line as unchanged, added or removed. The whole comparison happens locally, so even sensitive text — private documents, internal config, unpublished code — never leaves your device.
There is no upload and no account; paste, compare, and the result is yours alone.
No. The diff runs entirely in your browser, so nothing you paste is sent anywhere.
Yes. Any text works — code, config, logs or documents are all compared line by line.
They mark which lines were added, removed or changed between the original and the modified text.
The comparison is local, so the practical limit is your device's memory rather than a fixed cap.