There is only one-hundred percent accurate way to determine if a person is a member of the Navy SEALs or not. This is through the Navy SEAL Database. The SEAL database includes the names of every man who has served as a Navy SEAL. However, there are a few gaps in time throughout history when files were either lost or damaged. But currently, the database contains less than 11,000 names of men who have served as Navy SEALs.
This database is used by the United States Navy and can be accessed by other Navy SEALs. Navy SEALs use this system to validate other Navy SEALs and to assure that people are not fraudulently claiming to be Navy SEALs. In fact, many false Navy SEALs have been identified since Navy SEALs gained access to this database.
The SEAL database was comprised based on records dating back to the 1940’s. There is a small gap during WWII when records were misplaced. However, the Navy SEAL database is considered to be the most accurate and professional database of its kind. In fact, it is the only database which the United States Navy recognizes as being official.
This database may not be accessed by common citizens. This is to protect the identities and privacy of those men who are listed. However, by contacting a Navy SEAL you can ask them to run the names of people who are claiming to be Navy SEALs and they can inform you if they are truly Navy SEALs or not.