New York generally has a higher cost of living than London, especially when it comes to rent. Numbeo and Expatistan are good resources for comparing specific expenses. Salaries tend to be higher in New York as well, but this doesn't always offset the higher costs, particularly for housing. London has the NHS, which is a huge advantage for healthcare costs compared to the US system. Consider your personal spending habits and priorities to determine which city is a better fit for your budget.