Free tools · Foreign examiners' citations
What other patent offices cited against the same invention.
When the same invention is examined in several countries, each office runs its own search, and they often cite art the US examiner never saw. Enter a US patent number below for what the EPO, CNIPA, JPO, KIPO and the international search cited against the family, with the documents not of record in the US listed first.
By patent number
One number, any format. Pick what you want to know about it, or ask for everything.
Free. Five lookups a day per visitor; fifteen with an email. The examiner's search log is read by a paid transcription, so it is limited to three new patents a day per visitor and twenty for everyone. A patent already read is always free and never counts. Resets at midnight UTC.
Every answer shown here, by email, with a link back. Also lifts your limit to fifteen lookups a day.
Deadline calculators
Dates in, dates out. The IPR one-year bar, the PTAB milestones, a contest's close in your own zone, the PCT national phase and the EP opposition window.
Date the complaint was served (35 U.S.C. §315(b)).
Date the IPR petition was filed.
The close as posted, Eastern Time.
Earliest priority date. 30 months for most offices; 31 for the EP and some others.
Date the mention of the EP grant was published. An opposition is due 9 months later (Art. 99 EPC).
Statutory and rule-based intervals, counted in calendar days; the PTAB lines are the usual milestones, and the Board's own scheduling order governs. Not legal advice. Feeds the invalidity search.
WO / PCT report reader
A WO number in; out: the international search report's citations with their X, Y and A categories and the claims each was aimed at, the earliest priority, the national-phase dates, and whether the US national phase has been entered.
International search report · EPO record
- X
- Y
- A
X: relevant alone. Y: relevant combined with another. A: background. Only the searching authority's own citations are listed, not the applicant's. National-phase limits vary by office; check the WIPO PCT time-limits table for the one you need.
Wayback date-prover
A URL in; out: the earliest archived capture of the page and its link, as a citable line for dating a manual, a datasheet or a product page. A capture proves the page existed by that date; it says nothing about when it was first published. Feeds the non-patent literature sweep.
From the Wayback Machine
About this tool
The tool reads citations recorded against every member of the family and marks which ones already appear among the US references of record. The rest were found by another office and never considered here.
Where the citing office assigned categories (X, Y, A), they are shown: an X citation was judged relevant on its own to at least one claim of the foreign application.
Questions
- Does an X citation in Europe invalidate the US patent?
- Not by itself. The claims may differ, and the EPO applies its own standards. An X citation tells you where to look first, nothing more.
- Why do foreign offices find different art?
- Different examiners, classification practice, languages and databases. A Japanese or Korean examiner searches the art of their own office first, and that art is often thin in US searches.