The wireless charging capabilities of the iPhone 8 and iPhone 8 Plus will reportedly receive a boost later this year, courtesy of a future over-the-air firmware update from Apple.
Right now, the iPhone 8 charges at a rate equal to that of the 5-watt USB Power Adapter that Apple provides with the iPhone. However, according to an early review of the device (no doubt with a tip-off from Apple), this will increase slightly later this year.