Free Patent Search

U.S. Patent Search
This searchable database is open to the public and run by the United States Patent and Trademark Office. The database includes information about all US patents, i.e., utility patents, design patents, reissue patents, plant patents and SIR (statutory invention registration) documents, from the first patent issued in 1790 to the most recent issue week. Full text search are available for patents issued since January 1976 to the present. But patents issued from 1790 to December 1975 are provided only in images so text search not available.

PCT Publication Search
The PCT database (Electronic Gazette) covers full text of patent applications both raised onto international stage under Patent Cooperation Treaty and published with expiration of 18 months from the earliest filing date. The database includes PCT international applications published from January 1997, and where applicable, republished from April 1998. The searchable full-text for international application is generally available 2 to 3 days after the publication date..

European Patent Search
This European Patent Office database provides access starting 1998 to all patents published in the preceding two years by any member state of the European Patent Office and the World Intellectual Property Organization (WIPO). This EPO database also selectively allows access to patents published worldwide since 1920 and documents published since 1970.

Google Patents Search
The database of Google Patents includes the entire collection of granted patents and published patent applications worldwide which belong to the public domain. US patent documents date back to 1790, EPO and WIPO to 1978. Optical character recognition (OCR) has been performed on the older US patents to make them searchable, and Google Patents has been used on all non-English patents to make the English translations searchable. Two letters country code followed by a specific publication number will let you download its pdf form.

Japanese Patent Abstracts Search
Japan Patent Office (JPO) provides searchable English database for Patent Abstracts of Japan (PAJ) published since 1976. Computer translated English full text is also available. Due to the translation work involved, the time delay between publication of an unexamined patent application in Japan and the availability of the corresponding PAJ abstract is approximately four months.