The research by MyVoucherCodes ranks 50 of the UK's biggest towns and cities on their nightlife by comparing the average price of a pint and a G&T, the cost of an average meal in an inexpensive restaurant, the initial taxi fare, and the average rate for a one-night hotel stay at the weekend.
The rankings also factor in the city's safety score index and the number of bars and clubs it has per 100,000 people.
Behind Swansea, Northampton places second on the rankings, followed by Derby, Middlesbrough and Nottingham. Popular party spots Blackpool and Brighton finish a little lower at 19th and joint 34th respectively.
Edinburgh ranks joint 34th and Manchester places 40th. London finishes 50th – bottom of the table – mainly due to the prohibitive cost of partying in the capital.
According to the new research, the average price of a G&T ranges from £2.60 in Southampton to £4.55 in London. Cambridge was found to have the best safety score, while Bolton was found to have the worst.
Despite its relatively poor position in the rankings, Brighton was found to have the most bars and clubs per 100,000 people: 131. By contrast, London was found to have just six bars and clubs per 100,000 people. It has recently been revealed that the capital is losing a pub a week, prompting Mayor Sadiq Khan to lobby the government for a reduction in pub business rates.
Meanwhile, the highest average nightly hotel rates were found in London (£158), Cardiff (£152) and Oxford (£152).