Chemistry, a dating site that is part of Match.com, is designed for people who are seeking help in getting to know someone online before meeting them for the first time.
It has over 8 million users on its online database.
It works with special algorithms that match users with potential dates.
Launched in 2004, OKCupid works with many populations of people.
Zoosk is a singles dating app that uses a behavioral matchmaking engine to pair users who its system indicates will be a good match.