KEST is owned by Multicultural Radio which owns several stations across the country. KEST broadcasts around the San Francisco Bay Area; its signal is 1000 watts. The station features programming from Bay Area Metro Radio and Sino Radio.
The station was signed on by a local church and began broadcasting in the 1920s. It was not very popular, but in 1939 was purchased by Sherwood Patterson, who changed the call letters to KSAN. New studios were constructed in the Merchandise Mart near Market Street; a 250-watt transmitter was installed in a tower on top of the building. Listenership dramatically increased with a format of popular music (evolving into rhythm and blues by 1955 or so) and disk jockeys such as Les Malloy, who would purchase the station himself in the early 1960s. Malloy changed the call letters to KSOL and strengthened the rhythm and blues/soul music format targeting the African-American community; the station launched the career of popular 1960s and 1970s musician Sly Stone, who was one of the station's DJs. The format changed to a general-market music format by the early 1970s.
In the early 1990s, KEST adopted a talk and world ethnic format and became part of Multicultural Broadcasting.