Kaitori Navi is an information and comparison website focused on Japanese online mail-in buying services, helping people find ways to sell unwanted belongings without visiting a shop. It reviews and ranks providers using independently gathered online feedback and reputation, alongside factors such as purchase prices, service speed, range of accepted goods, and business scale. The site covers services from companies including Bookoff, Suruga-ya, Amazon, Kaitori Ouji, and Brandear, rather than presenting itself as a buyer of goods.

Its guides address selling books, manga, specialist publications, CDs, DVDs, games, trading cards, figures, clothing, branded goods, precious metals, golf equipment, electronics, and household appliances. Visitors can compare provider reviews and category rankings, explore tips for improving sale prices, and learn about identification documents, shipping and collection options, ineligible items, campaigns, and the steps involved in a transaction. Kaitori Navi is designed particularly to help first-time users assess their options, understand potential costs and limitations, and choose a service suited to the items they want to sell.