Text compare — before and after, side by side
Paste the original on the left and the revised copy on the right. CheckDiffs is a free, private in-browser text compare: Monaco shows every insertion and deletion so you catch the swapped comma, deleted disclaimer, or soft rewrite that changes meaning. No account. Nothing uploaded for basic compare.
Built by FT for clear before/after review of any draft — see About.
Open text compareWhen paste-and-diff beats scrolling
Drop the older draft, email, contract clause, or plain-text export on the left; put the updated copy on the right. Removals lean red, additions lean green. Previous / Next walks each hunk so you are not hunting through a wall of highlighted HTML. People use it for article drafts, support macros, meeting-note cleanups, localization string sets, teammate edits — and yes, AI-rewritten prose from ChatGPT or Claude against the original when that is the job at hand.
Private drafts stay local
Contracts and customer emails often should not leave your machine. CheckDiffs processes basic compare client-side. Analytics may record anonymous page views; your pasted text is not part of that. Privacy · About
Free forever for basic compare
Basic side-by-side stays free. Pro ideas (export, ads-free, AI summary quota) are TBD — we will not put a fake Stripe button on the page. Until then: paste, compare, done.
FAQ
Is my text uploaded when I compare?
No. CheckDiffs runs the comparison in your browser with Monaco. Your pasted content stays on your device for basic side-by-side. Open DevTools → Network while you type if you want to verify.
Is text compare free?
Yes. Basic side-by-side is free forever, no account. Pro extras (export, ads-free polish, AI summary quota) are TBD — no fake checkout today.
How is this different from Word track changes?
Track changes lives inside a document. CheckDiffs is paste-and-compare for any plain text: two clipboard versions, one red/green diff, jump between hunks. Ideal when you only have the before and after strings.
Can I compare code as well as prose?
Yes. Switch the language selector for JavaScript, TypeScript, Python, JSON, and more — or stay on Plain Text for articles and emails. Same private engine.
Leave language on Plain Text (or switch as needed) at checkdiffs.com.