https://www.techradar.com/news/2018-iphones-may-come-with-faster-wireless-charging

Last year's iPhone range - the iPhone 8, iPhone 8 Plus and iPhone X - all sported wireless charging for the first time in the company's phone-making history. That said, the speeds offered aren't as fast as wireless charging on other top-end phones, but that may change for the upcoming iPhones.

Apple's latest devices launched ready to support 5W chargers and a software update made the phones able to support 7.5W options. But Samsung's wireless charging compatible devices support 15W, which means each of those products can charge up faster.