Throughout the 1980s, the station played an eclectic mix of R&B, jazz and soft pop, reflecting the diverse music culture of the Bay Area. KBLX was the inspiration for radio stations throughout the country for the creation and launch of various adult contemporary radio formats, from New AC (Jazz) to soft rock AC to Urban AC (R&B), the latter which KBLX modified its format to years later. (The Urban AC terminology did not exist until 1988). Even then for some time the station played mostly smooth R&B, rarely playing any uptempo R&B, current or old school, unlike its Urban radio competitors such as now-defunct KSOL, or its current competitors, such as its Hip Hop counterparts KMEL and KYLD, Urban AC KISQ and its smooth-jazz arch-rival, KKSF.
Even when KBLX modified its format to Urban AC in the 1990s, the station continued to play jazz music in rotation -- and this practice of mixing R&B and Jazz songs on radio playlists has occurred on few Urban AC radio stations in some markets. However, KBLX played more R&B songs than they did jazz; the ending result of this was that it gradually phased out from the era of an R&B/jazz playlist in recent years. From then on, KBLX has evolved into a true Urban AC station today (like the stations in other markets) -- playing current and old school R&B, including adding uptempo R&B songs as well to not only match its competitors, but to fill in the void of the Urban AC format as a true R&B station in years. Despite the changes, it still advertises itself as a "Smooth R&B" station, reflecting "The Quiet Storm" heritage handle.
KBLX is the Bay Area's only commercially Black-owned and operated radio station.
From the inception, KBLX also had a simulcast on 1400 AM until 1994, when sister station KVTO was launched.