Whitepages.com, 411.com and AnyWho.com are two of the most comprehensive free phone directories. Business information is available on YellowPages.com and LinkedIn.com. These websites are useful for phone number and address lookup, as well as for reverse lookup.
Whitepages gets its data from published phone books, contest entries and subscription forms filled out by consumers. It may also get information from social media profiles.
As of January 2016, YellowPages.com claims to have 20 million business listings that users can search on its website or using its YP app. The site organizes the listings according to categories such as restaurants, home improvement and automotive.
Individuals can also use Facebook to find phone numbers that are listed on a person's or business' account. To find the owner of an unfamiliar number, Facebook users can type it into the search field to see if it is associated with a profile.