The Welsh city came top in a league table of the most sociable locations in the country compiled by the website, which looked at the social habits of its 160,000 members.
The ranking was based on the average number of days and nights out and social events that residents of each city went on or attended.
Cities in the North made up the rest of the top three with Leeds closely following Cardiff in the list and Newcastle rated third.
According to the study those in Cardiff go out 28 per cent more than the UK average, while Glaswegians socialise 58 per cent less than the average. Nottingham and Birmingham were also judged to be under the average when it comes to nights out its residents go on.
London only 7th most sociable city
Sanchita Saha, the chief exec of CitySocialising said it was no surprise the Welsh capital had come out on top: "Cardiff is definitely one of our up and coming cities when it comes to being sociable. We’re hosting around 40 events a month for our members to keep up with demand there."
“The most surprising finding was that London, where we arrange over 50 events a month and viewed by many as the place in the UK with the biggest social buzz, actually only came in seventh,” Saha added.
Although London might have not been judged to be the most sociable, the capital's residents were declared the most likely to use online tools to interact and arrange to meet up more than others in the UK.
Cardiff has seen an increase in visitors and restaurant and bars choosing to locate there since the Cardiff Bay re-development and the city now boasts over 70 restaurants as well as hundreds of bars and hotels.
The UK's Most and Least Sociable Cities, according to CitySocialising:
1 Cardiff
2 Leeds
3 Newcastle
4 Liverpool
5 Bristol
6 London
7 Brighton
8 Manchester
9 Edinburgh
10 Birmingham
11 Nottingham
12 Glasgow