The station began broadcasting in 1990 when its parent station Downtown Radio ceased simulcasting and split its AM and FM frequencies into two separate services. Downtown Radio continued on 1026 kHz AM and on some FM frequencies and Cool FM was created to broadcast on the 97.4 MHz FM frequency, initially in the Greater Belfast area only.
Cool FM usually plays chart and contemporary hit music, but also features some specialised hours such as Cool of Rock on weekday mornings and Cool Goes Quiet (easy listening classics) on Monday - Thursday nights. The station's Newtownards studios are based on the Kiltonga industrial estate.
All but one of Cool FM's programming is locally presented and produced from its Newtownards studios. The exception is The Vodafone Big Top 40 on Sunday afternoons, produced by Global Radio at its main London studios for broadcast on 145 commercial radio stations in the UK.
Local news bulletins air on the hour between 6am and 10pm every day (there is no 7pm bulletin on Saturdays). On weekdays, there are extended bulletins at 1pm and 5pm and headlines on the half hour during breakfast and drivetime.