You can search for US patents using various methods and tools, depending on your needs and preferences. Here are some of the most common methods:

• Patent Public Search: A web-based patent search application that allows you to query three databases at once: US-PGPUB (pre-grant published patent applications), USPAT (all US patents), and USOCR (scanned pre-1970 US patents). You can use simple or complex search queries, and use search indexes (field codes) to narrow down your results by specific criteria, such as title, inventor, date, classification, or abstract. You can also access and view the full text and images of the patents, and download them in various formats. ¹
• Google Patents: A free online service that lets you search and read the full text of patents from around the world, including US patents. You can use keywords, phrases, operators, or filters to refine your search, and view the patent family, citations, classifications, and related documents of each patent. You can also use Google Scholar to include non-patent literature in your search. ³
• PAIR (Patent Application Information Retrieval): A secure online system that provides access to patent application status and information. You can use PAIR to check the status of your own patent application, or to view the public data of other applications, such as bibliographic data, transaction history, continuity data, and image file wrapper. You need to register and log in to use PAIR. ¹
• Public Search Facility: A physical location at the USPTO headquarters in Alexandria, VA, where you can access patent and trademark information in various formats, such as online, microfilm, and print. You can use the same databases and tools as the USPTO examiners, and get assistance from trained staff. The Public Search Facility is open to the public from Monday to Friday, except federal holidays. ¹
• PTRCs (Patent and Trademark Resource Centers): Libraries or institutions across the US that provide access to patent and trademark resources and services. You can use PTRCs to search for patents using online or print materials, and get training and guidance from librarians or specialists. You can find your nearest PTRC on the USPTO website. ¹