It launched in 1995 and is now available in 24 different countries.
Members set up a profile, upload photos and can then search through profiles to find a good match.
It was originally a service called Just Say Hi, but the site transitioned to Mingle2 in 2008 and now works with many populations of singles.
My Social Calendar connects people with similar social interests by planning fun events for socializing. C., Philadelphia, Detroit, New York City, Boston, South Florida, Charlotte and Los Angeles.
It works with special algorithms that match users with potential dates.
Launched in 2004, OKCupid works with many populations of people. It uses a compatibility matching system to link up people with complementary personalities and lifestyles and has worked with millions of users over the past 15 years.
More traditional sites may offer anything from a simple search to a highly specific advanced search.