NSN Lookup is an online resource for military and government supply-chain information, helping users identify and research items catalogued by National Stock Number (NSN). Its search tools support queries by NSN or NIIN, part number, CAGE code, and keywords, with advanced search and autocorrect options. Results can provide item descriptions, characteristics, technical specifications, and information on pricing and availability.

The site brings together reference data and marketplace inventory, including links to NSN inventory and DLA-related resources. It also offers equipment intelligence, technical manuals, and supply-chain data covering air, land, and sea platforms. Reference topics include NATO stock numbers, Federal Supply Groups, CAGE and NCAGE codes, WEBFLIS, FEDLOG, military terminology, and item identification. Its database spans more than 37 million NSNs across categories such as aerospace components, electronics, vehicles, tools, medical supplies, and clothing. NSN Lookup is designed to support item identification, procurement, logistics, and inventory research. The site also links to merchant products and discloses that purchases may generate affiliate commissions.