The catalog
Patent invalidity dossiers.
7,163 patents in the database, sorted by number of on-file litigation cases. Of these, 2,988 have at least one tracked case across 6,606 litigations.
Demand letter analyzer
You got a patent demand letter. Now what?
Paste the letter — we extract the asserted patents, identify the asserter, characterize their litigation history, flag validity vulnerabilities, and draft a sample response letter your attorney can review. Free, private, ~2-3 minutes.
Analyze a patent
Drop a US patent number — we’ll verify it on Google Patents and generate the full invalidity dossier.
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I'll verify the details against live sources before summarizing. One more check for any recent (2026) litigation activity. Summary — US Patent 4,936,494 Sources used: the full patent text at https://patents.google.com/patent/US4936494/en…
View full analysis →added 9/30/2026I'll search for this specific patent number across the requested sources. Let me confirm the litigation posture with a targeted search. US Patent 4,965,725 — Analyst Summary Search scope note: I searched for the identifier "4965725"…
View full analysis →added 9/26/2026I'll verify the details and check for any litigation or docket activity. US Patent 5,063,552 — Verified Summary Source: Google Patents full text (authoritative for this analysis): https://patents.google.com/patent/US5063552/en…
View full analysis →added 9/28/2026I'll verify the patent record and check for any litigation/docket activity. Let me check the specific litigation records referenced for this patent. US 5,073,543 A — Verification Summary Important caveat up front: I did not find any 2026…
View full analysis →added 9/28/2026I'll run searches to check for any litigation/docket activity and confirm the bibliographic data. Let me do one more targeted check for any litigation or PTAB/Court of Appeals activity. Search results: no litigation found Before the…
View full analysis →added 9/24/2026I'll search for the specific patent number as instructed. Let me check for litigation/docket activity and confirm the bibliographic details. Search method and limits I ran literal-string searches on identifiers 5202231, US5202231, and…
View full analysis →added 9/30/2026I'll verify key bibliographic data and check for any current litigation posture for US 5,220,501. Let me pull the actual claim set for this patent, since the supplied text is truncated before the claims. Let me retrieve the full claim set…
View full analysis →added 9/24/2026I'll search for authoritative records on this patent number before summarizing. Let me pull the claim text and check litigation/docket records. US 5,287,272 — Analyst Summary Sources consulted (fetched 2026‑04‑26): the patent full text you…
View full analysis →added 9/27/2026I'll search for authoritative information on this specific patent number and any related appellate dockets. Now let me check the appellate dockets referenced on the patent page and any 2026 activity. Let me verify the appellate outcome and…
View full analysis →added 9/27/2026I'll search for the specific patent number and any related litigation. US 5,334,821 — Summary Important caveat on identifiers: A search for "5334821" also surfaces JP 5334821 B2 (a 2013 Japanese patent to TOWA Corporation for a…
View full analysis →added 9/24/2026I'll verify this patent against live sources and check for any 2026 litigation activity. Let me check specifically for any 2026 litigation or Federal Circuit activity. US 5,382,784 — Verification Summary Sourcing note: I checked Google…
View full analysis →added 10/1/2026I'll search for this specific patent number across the requested sources. Let me verify the litigation/docket angle and the assignee status with targeted searches. US Patent 5,389,981 — Analyst Summary Sourcing note: The authoritative full…
View full analysis →added 9/26/2026I'll search for the specific patent number and related docket information. Let me check for any CAFC 2026 appellate activity and the known district court litigation. Summary of U.S. Patent 5,418,713 I searched for this specific number…
View full analysis →added 9/24/2026I'll search for this specific patent number and any related CAFC 2026 docket activity. Let me dig into the litigation references and check for any current docket activity. Let me try to retrieve the remainder of the claim set (claims…
View full analysis →added 9/27/2026I'll search for this specific patent number across available sources before summarizing. Let me retrieve the claim set and docket/litigation history for this specific patent. Let me try to retrieve the full claim listing to identify all…
View full analysis →added 9/29/2026I'll search for authoritative records on this specific patent number, including any current litigation/docket activity. US 5,492,806 A — Summary Note on sourcing & the requested docket search: The bibliographic and claim data below come…
View full analysis →added 9/30/2026US 5,499,252 A — Verified Bibliographic Record Search note up front: I found no CAFC 2026 docket activity or any district-court record naming patent 5,499,252 literally. Google Patents' family page (family ID 26566990) carries a "Family…
View full analysis →added 9/28/2026I'll search for authoritative records on this specific patent number, including its claim set (which isn't included in the text supplied to me) and any 2026 litigation. Now let me check for any 2026 CAFC litigation or docket activity…
View full analysis →added 9/30/2026I'll verify the patent details against live sources and check for any 2026 CAFC docket activity. Let me check for litigation and any recent docket activity. US Patent 5,545,531 — Verified Summary I searched for the specific number 5545531…
View full analysis →added 9/11/2026I'll search for this specific patent number and related litigation information. Let me check for CAFC litigation and get the claim text. Let me try to retrieve the actual claim text and check for any 2026 CAFC activity specifically…
View full analysis →added 9/28/2026