Tools / Diff checker
Diff checker
Compare two versions of any text, whether it is code, a config file, or a document, and see exactly what changed. Choose a unified or side-by-side view, ignore whitespace or case, spot changes within a line, and download the result as a .patch file.
Compare text without leaving the page
This free online diff checker uses the same Myers shortest-edit algorithm that powers tools like git. Paste an original on the left and a changed version on the right; the result pane shows hunk headers, dual line numbers, and add/remove coloring with +N / −N stats.
Everything is client-side: useful for secrets, drafts, or any content you would rather not paste into a third-party website. Copy the unified diff to your clipboard or download a .patch ready for review.
FAQ
Is my text uploaded to a server?
No. The diff runs entirely in your browser, so the original and changed text never leave your device.
What format is the downloaded .patch file?
A standard unified diff (--- / +++ headers and @@ hunks), the same format git apply and patch(1) expect.
When should I use ignore trailing whitespace or ignore case?
Turn them on when you care about content rather than formatting, for example when comparing logs that pad lines differently, or prose where capitalization differs.
What does within-line highlighting do?
On paired delete/insert lines it runs a character-level Myers pass and marks the characters that actually changed, so you can spot a one-word edit without re-reading the whole line.