Espacenet Worldwide Patents
This is the single, most comprehensive, free patent database available on the internet. The European Patent Office has developed a worldwide patent database of over 80 million patents from over 90 countries, many with full-text page images, available at no charge. Formerly, this database was known as esp@cenet.
The starting date varies greatly by country, with the earliest being 1836 for the United States. The availability of any given field also varies greatly by county and time period. For example, only about 50% of the patents have a title field and only 33% have an English abstract. Please review the Coverage of the Worldwide Database for details.
Comprehensive topical searching is best done via the Classification Search query screen using the new Cooperative Patent Classification system. However, this approach requires careful research to identify all appropriate codes and skill in using Boolean logic to combine them properly.
This site permits downloading of the full-text of entire patents with a single command, including U.S. patents. Until one downloads the patent text, one can only print a single page at a time. To download the full-text in pdf format, click on the patent title from any search result listing. Then click on the Original documents link on the left, then click on the Download link directly above and to the right of the displayed text. Do NOT use your browser's print, download, or save commands. Once it is downloaded, one can print the patent pdf file from within Adobe Reader.
A useful guide to the patent procedures and numbering systems used by different countries is the publicly available, 2007 edition of the Derwent global patent sources: an overview of international patents.
For more information and help:
Varies by country, oldest is 1836 for U.S. patents.