Free tool · Patent claim diff
See exactly what changed.
Paste two versions of a patent claim — or any patent prose — and see a word-level redline. Useful for tracking claim amendments during prosecution, preparing IPR petitions, and drafting continuations.
Old version
New version
Diff runs entirely in your browser — nothing is sent to a server. Useful for tracking patent prosecution amendments, IPR challenges, and comparing draft claims to issued claims.
Useful for
- Tracking USPTO office-action amendments — paste the original and amended claim, see which words were added to overcome the rejection.
- IPR preparation — compare your accused infringement reading against the literal claim text to identify defensible deltas.
- Continuation drafting — diff your continuation claims against the parent claims to confirm you're not adding new matter.
- Claim-construction prep for Markman — see what each side proposes vs. the original claim language.
FAQ
Frequently asked questions
Why compare two versions of a patent claim?
Comparing versions shows exactly what changed during prosecutionprosecutionThe whole process of moving a patent application from filing through grant or abandonment at the USPTO.Read more →. Additions narrow the claimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → and can trigger estoppel; deletions broaden it. A word-level diff is essential for tracking amendments, IPR prep, and continuationcontinuationA new patent application that claims priority to an earlier still-pending parent application.Read more → drafting.
What is prosecution history estoppel?
When you narrow a claimclaimA numbered sentence at the end of a patent that legally defines what the inventor owns. The most important section.Read more → during prosecutionprosecutionThe whole process of moving a patent application from filing through grant or abandonment at the USPTO.Read more → to win allowance, you generally can't later recapture the surrendered scope under the doctrine of equivalentsdoctrine of equivalentsExtends infringement beyond the literal claim language — if a competitor's product does substantially the same thing in substantially the same way, it can still infringe.Read more →. A claim diff makes those narrowing amendments visible so you can see what was given up.
Where this fits · The patent process
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