The station signed on the air in 1982 as KNNN, a Spanish-language station. It made the evolution to its current format in 1988. In 1999, Clear Channel added the station to its Phoenix cluster.
The station is anchored by the highly successful "Beth and Bill Show," its Morning Drive Program since approximately 1990 (hosted by Beth McDonald and former KPNXmeteorologist Bill Austin). The show was renamed Beth and Friends after Bill Austin retired in early 2010 due to his cancer. On June 2, 2010, Bill Austin (real name William Austin Waggoner) died of bladder cancer.
Since January 2016, KEZ reimaged using Cam Brainard and Rachael Mcgrath, along with a jingle package change from RW One CHR to RW One AC and changed their positioner to a Better Variety For A Better Work Day. KEZ uses the WLTW logo melody in its jingle presentation.
Each year after Thanksgiving, the station has a tradition of playing "Non-Stop Christmas Music". Beth and Friends still air as regularly scheduled but the songs they play are strictly Christmas music.
Since 2008 the music has started prior to Thanksgiving.
The station competes with two of its sister stations. One competitor is KMXP, which is Hot AC and excludes the 1970s' hits on KESZ. Another competitor is KYOT-FM, which offers a Rhythmic AC format (although it was a competitor for many years with its Smooth Jazz/Smooth AC format).
KESZ's HD Radio signal is multiplexed. The main signal is a simulcast of KESZ's adult contemporary programming. The second channel carries KEZ's Classic Channel programmed by Clear Channel's Format Lab classic hits format consisting of songs from the 60s, 70s and 80s.