What ClaimMark-A Prior Art Search searches: US patents granted from 1836 onward and US applications published from 2001 onward.

Beside it: a separate non-US list, ranked on its own.

Each search also shows non-US patent documents from a second index, as their own list with their own ranking and the same publication-date limit. They are never merged into the US results, and families already in the US results are not repeated. When the non-US index cannot answer in time, the search says so and the US results stand.

European Patent Office

7,453,725 publications from December 20, 1978 to September 23, 2026; 4,784,525 of them with their claims in the index (full text from the EPO's bulk data), the rest with bibliographic data and an abstract where one exists.

Other offices

76,911,519 patent families of 103 offices that have no US or European member, one record per family with its title and abstract only (no claims or description). Largest: CN 43,753,677, JP 12,574,398, KR 3,751,200, DE 3,195,322, GB 2,019,193, FR 1,495,458.

Search by meaning only

This list is found by meaning (semantic retrieval), not by keywords, from each record's title, abstract, and independent claims; the European description is not searched. 75,908,502 records are searchable this way. The 8,456,742 families of other offices with no English title or abstract are not found.

Updates

Not yet weekly: published through September 24, 2026.

What's included: 21,480,665 documents of 9 types.

Most of what you will find is utility patents and published applications. The smaller types are here too, because an examiner can cite any of them against you.

First and last numbers are the lowest and highest in each series. Dates leave out the 39 placeholder records (utility patents 5, defensive publications 7, trial voluntary protest publications 27), which stand in for a withdrawn number or carry no real date; they are counted in Documents. See the known limits below. 1 further document fits none of these types.

Documents by decade: 15,297,437 of the 21,480,665 were published from 2001 on.

Counted by publication date. Applications start in 2001, when the USPTO began publishing them.

The 39 placeholder records have no real date, so they are left out here and counted in the total documents. The few surviving patents granted before July 1836 are counted in the document-type table above, not here. One document that fits no type is counted in the total documents only.

Where the text comes from: USPTO full text from 1976, machine-read scans before that.

What each era's records contain, and what that means for your search.

The share of documents in each group that have each field. Recent records are close to complete. Records from before 1976 have their text, claims for most, and classification, but little else.

* The 694 trial voluntary protest publications, the only applications published before 2001. A text field counts as present when it has at least one word.

Title

Titles before 1976 are machine-read, so an old title can carry a reading error.

Abstract

Most patents granted before 1976 have no abstract, so their results show the opening of the description instead, labeled as machine-read text.

Description

The description is the main text you search by meaning and by words in every era.

Claims

Claims before 1976 are cut from the machine-read text; where none were found, the patent can still be found through its description.

Independent claims

A claims search compares your claims with these, so it works best on documents that have them.

CPC classification

CPC filters work in every era, because the codes come almost entirely from the USPTO master classification file.

Applicant or assignee

Records before 1976 name no applicant, and many later records have none either, so don't rely on a company name to find or rule out a document.

Application number

Patents granted before 1976 have no application number in the index, so look them up by patent number.

Priority date

Where an old record has no priority date, judge how early it is from its publication date.

Examiner citations

The examiner check works on patents granted from 2001 on, the only records whose sources say which citations the examiner made.

Other citations

Citations by the applicant, plus every citation whose source does not say who made it, which is every citation before 2001.

Searchable by meaning

Documents with this are found by meaning as well as by words.

What's not included: US design patents, non-patent literature, US patents granted before 1836 apart from a few survivors, and the claims and descriptions of non-European foreign documents.

• US design patents, in every era. Design documents in the index: 0. The weekly updates have set aside 4,776 new design patents since September 29, 2026.
• Foreign patents and applications, in this US index. Documents in it with a non-US number: 0. They are searched in the separate non-US index described above and shown as their own list; for offices other than the EPO, that index holds titles and abstracts only.
• Non-patent literature: journal articles, books, product manuals, websites, standards. None is indexed, and citations of it are not stored. A white paper you never heard of still counts against your patent.
• US patents granted before 1836, apart from a few surviving earlier patents. Most records of those patents were lost in the December 1836 Patent Office fire.
• Withdrawn patents. The USPTO does not publish them in its bulk files, so their numbers have no document here.

So a search here is one search among those your invention needs, not a clearance.

Known limits in the data, measured and stated plainly.

• Reading errors before 1976. 3,939,654 documents have machine-read text, and their titles, text, and claims contain OCR errors. How often is not measured.
• Placeholder records. 39 records are stand-ins rather than documents with a real date (kind I5: 27, kind T: 7, kind A: 5): 5 machine-read records titled exactly "Withdrawn", which hold the place of a withdrawn patent number, and 34 dated 1900-01-01, the source's stand-in for an unknown date. They are counted in every total and left out of the first and last dates and the table of documents by decade.
• Approximate dates. US patents issue on Tuesdays. 5,357 grants dated from 1848 onward fall on another weekday, so their dates are wrong or approximate: before 1976 5,356, 1976–2000 1, 2001 onward 0. Some keying errors in USPTO dates from 1976–2000 were corrected from the dates of neighbouring patent numbers.
• Numbers with no document. Within each numbered series, 79,235 numbers between the lowest and highest have no document in the index. A number can be missing because the patent was withdrawn, because it was never issued, or because the record is missing upstream; the index cannot tell these apart. Details are in the table below.
• Who cited what, before 2001. The sources for older patents don't say whether the examiner or the applicant cited a document, so every citation before 2001 is listed as an "other" citation, and the examiner check covers patents granted from 2001 on.
• Unclassified. 1 document has a kind code that fits none of the types above. It is searchable like any other.

Number ranges by series

19 utility numbers belong to two documents (a pre-1976 reexamination certificate carries the number of its patent) and are counted once. Published applications are numbered by year, so no single range applies; the first is US20010000001A1 and the latest US20260324525A1.

How it stays current: the USPTO's weekly files, applied as they appear.

• Weekly USPTO feed. The USPTO publishes new grants every Tuesday and new applications every Thursday. The index checks for new files every day at 10:00 UTC and applies each new file once, including any corrected copy of a file. Since September 29, 2026 it has applied 6 weekly files and added 50,108 documents.
• Search by meaning, normally the same day. A new document can be found by its words as soon as it is loaded. It can be found by meaning once it has been processed, which runs every day at 13:00 UTC. Documents waiting for that step now: 0.
• Your search record names the date. Every search record states the index build and the date it is updated through, so you can show what your search could and could not have seen.

This page is generated from the index itself. Last generated October 15, 2026, with grants through October 13, 2026 and applications through October 15, 2026.