Nope, it's not KitKat, but hey,
beggars owners of older Android handsets can't be choosers. If you've been using AT&T's version of the Samsung's waterproof Galaxy S4 Active, you're in luck: Android 4.3 is starting to roll out in the form of an over-the-air update. As you're probably aware by now, the update keeps the phone in Jelly Bean territory, but brings a good deal of improvements, including OpenGL ES 3.0 support, Bluetooth Smart technology, enhanced notifications and 1080p Netflix streaming. Good luck with that 772MB download, and do let us know how it goes.
Samsung Galaxy S 4 Active