The United States government and SSNValidator.com both offer free Social Security number searches, but both are limited in the features that are offered. Due to privacy concerns related to Social Security numbers, neither service offers a browsable database of SSNs, but they instead offer validation of SSNs.
Searching for a SSN issued before 2011 on the SSNValidator.com website returns an approximate issuance date of the SSN, the state in which it was issued and whether or not the owner of the SSN is reported as deceased. The United States government search database is more complex and requires registration. It is used to verify that a given name and SSN match and are valid. This service is used by employers when validating existing or new employees.