The station began with an Adult Contemporary format as WYKY, "Key 100.5", then for several years aired a "hot talk" format as "100X,", with a schedule including the Howard Stern and Don & Mike shows and sports programming from Sporting News Radio and later Fox Sports Radio. By the mid-2000s, the station would morph into an all-sports format, with both national and Wisconsin-based programming. WTLX would take affiliation with ESPN Radio, whose programming had been airing in Madison on rival station WTSO, on January 1, 2009. Along with that affiliation change, WTLX's transmitter and city of license moved from the Columbus area (northeast of Madison) to the Madison suburb of Monona, where it transmits from the water tower at the Mendota Mental Health Institute.
WTLX's current daily schedule includes programming from ESPN Radio as well as Wisconsin-based programming originating from Milwaukee-area sister station WAUK (540), including "The World's Greatest Sports Talk Show with Steve 'The Homer' True" (3PM-6PM), and "The Badger Hour" (6-7PM).
Weekday programming begins with Mike and Mike in the Morning, followed by The Herd with Colin Cowherd, Scott Van Pelt, Homer, The Badger Hour with Lance Davis, and In the Trenches. Specialty programming includes the Miller Light Football Show, Pat Richter, Wisconsin College GameDay, and High School Hysteria.