Search the full text of millions of United States Patents from 1790 until the past few months using Google Patent Search.

Using Google Patent Advanced Search, you can search by:

• Patent number
• Patent title
• Inventor
• Assignee
• U.S. classification or International classification
• Document status (issued patents or applications)
• Patent type
• Issue date or filing date

Viewing and downloading patents is simple - just click Download PDF on the patent's about page.

The European Patent Office Database, esp@ce.net offers a way to search the patents of many (92) countries at once.  A caveat with searching this way is that the search may not be comprehensive.

Use Quick Search, Advanced Search, Number Search, Classification Search, or the new Smart Search.

To view and download patents, click on Original document for a .pdf file.

The United States Patent and Trademark Office (USPTO) offers
nearly complete and up-to-date patent information through the
USPTO Patent Full-text and Image Database.

Search Issued Patents or Patent Applications using Quick Search,
Advanced Search, or Patent/Publication Number Search.

You will need to install a browser plug-in to view the images.

Use this search engine when you want to search the most current applications, or if you want to see a list of patent numbers that are withdrawn, or missing from the database.