Critical Date SearchPrior art from before the critical date, verified word for word.
When an assertion entity sues your client, we search the asserted patent and deliver claim charts within 48 hours. Every quotation is checked against its source document, every reference is dated, and art already cited during prosecution is screened out.
✓ All quotations were confirmed in the source documents
Internet Archive capture · 44 pp.262 days earlier
Internet Archive capture · 74 pp.401 days earlier
A report your team can use the day it arrives.
Each report covers the asserted independent claims of one patent. You get the documents, the dates and the exact passages, organized element by element.
Claim charts
Every claim element paired with verbatim passages and pin cites, so you can go straight to the page.
Dated evidence
Publication dates and independent archive captures for each reference, plus how far each one predates the critical date.
Of-record screen
Patent and non-patent art already before the examiner is identified and excluded, so the report covers new ground.
Beyond patent databases
Product manuals, standards contributions, datasheets and trade press: the places where commodity searches stop.
If a quotation can't be verified, it doesn't ship.
Courts have sanctioned filings with citations no one checked. Our reports go through a verification gate before anyone sees them.
Search
We read patents, standards, product documentation and archived web pages, in English and other languages, focusing on art the examiner never saw.
Verify
Software retrieves each cited document and matches every quotation against its text and page. Anything that fails is removed, never paraphrased into place.
Deliver
You receive a PDF with a verification summary, a coverage grid, the claim chart, the reference copies and a methods statement, within 48 hours.
Simple, published, per patent.
Assertion campaigns name many defendants on the same patent. Our pricing reflects that, so co-defendants and joint-defense groups pay less.
- Asserted independent claims
- Full report and reference copies
- Delivered within 48 hours
- Same patent, same campaign
- Identical report, licensed to your client
- Same-day delivery when available
- Licensed to every member of the group
- One point of contact
- Delivered within 48 hours
Invoiced on delivery, so you review the report before you pay. Additional claims, patents or foreign-language translations are quoted on request.
Is this a legal opinion?
No. Reports contain search results: documents, dates and passages. We don't give opinions on validity, infringement or claim construction, and no attorney–client relationship is created. Your counsel decides what the art means.
Who performs the search?
Critical Date Search is AI-native. Searches are run by an AI research system, and every citation must pass automated verification against the source document before a report is released. You deal directly with Eric Keller, who runs the service.
How do you establish dates?
From the date printed on the document and, where available, independent captures by the Internet Archive. The evidence for every reference is listed in the report next to the reference, with a link to the copy we relied on.
Is our engagement confidential?
Yes. We never disclose who engaged us or what you told us. The search itself covers public prior art on a public patent, so the same search may be licensed to other defendants in the same campaign. That is why co-defendant pricing exists.
What if the art isn't strong?
You'll see it before you pay. Every report states plainly which claim elements have verified passages and which don't.
Can you search other patents or claims?
Yes. Send the patent number, the asserted claims if known, and your deadline. We'll confirm scope and price before starting.
Send us the patent number.
Include the asserted claims if you have them and your answer deadline. We'll confirm scope and timing by email.
Eric Keller · Critical Date Search