Best answer: The Smart Battery Case should work with the iPhone X, though the case won't fit as well as if you were using it with an iPhone XS. Because of this, you might still want to get a case meant for the iPhone X, like the Mophie Juice Pack Air.Get it in black: iPhone XS Smart Battery Case ($129)Get it in white: iPhone XS Smart Battery Case ($129)Best alternative: Mophie Juice Pack Air ($100)