Lens serves global patent and scholarly knowledge as a public good to inform science and technology-enabled problem-solving.
The United States Patent and Trademark Office (USPTO) Public Search Facility
The most comprehensive patent searching tool available for free. It is developed and provided by the EPO (European Patent Office). It can find more than 120 million patent documents from over 100 countries.
Google Patents is a search engine from Google that indexes patents and patent applications.
Search 2 million Canadian patents from 1869 to the present. Full-text documents are available from 1869 forward. This database is produced by the Canadian Intellectual Property Office (CIPO) and is updated weekly.
The official database of the World Intellectual Property Organization (WIPO). Explore 65 million patent documents from more than 51 regional and national patent offices. Major national collections include Canada, China, European Patent Office, Japan, Korea, Russia, the U.K, and the U.S.
InPass is a full-text search of all Indian patents and Patent Applications.