Who was that unknown caller? A phone number lookup from RevLookup can answer it for any U.S. number, and the owner's full name is free to see. Enter the digits, run the search, and look for extra details beside the name. There is no sign-up and no credit card to hand over. The service operates independently, so accuracy and transparency are not traded for corporate favors. It also reaches beyond the States, with country codes for Canada, the UK, Norway, Egypt and more. That makes it handy for checking missed calls, voicemails and unfamiliar texts.