Yes, the iphonex can use a 30w charger.
The iPhone X features a full-screen design in the form of a \"fringe screen\" that does away with Apple's decade-old bottom Home button. Available in 64GB and 256GB versions, it comes in silver and dark space grey. The screen measures 5.8 inches, weighs 174 grams, is 143.6 mm high, 70.9 mm wide and 7.7 mm thick, and has a resolution of 2436 x 1125 pixels.