[Update] The 18W charger you got with your iPhone 11 Pro won't officially fast charge your iPhone 12

iPhone 12 box
iPhone 12 box (Image credit: Apple)

What you need to know

  • Apple isn't shipping chargers with the new iPhones because everyone already has one.
  • But fast charging iPhone 12 and iPhone 12 Pro requires a 20W USB-C charger.
  • That means the 18W charger isn't officially supported, but it's still pretty fast.

Our initial testing of charging an iPhone 12 using an 18W charger instead of a 20W charger shows that you can charge an iPhone 12 from 2% to 59% in about half an hour. As more people test this in different scenarios, this should become a little clearer. However, this is about as fast as initial tests of the 20W charger that we've seen. As it stands, per this article, Apple is explicitly clear that you will need a 20W (or higher) power adapter to fast charge your iPhone 12, and that the 18W charger does not officially support fast charging the iPhone 12. Unofficially, it looks like you'll be able to get pretty good/very similar charging speeds from the 18W charger. Why not pick one of our favorites chargers, perfectly suited to charging iPhone 12?

Looking to fast charge that new iPhone 12 or iPhone 12 Pro? Great – you can just use that 18W charger that came with your iPhone 11 Pro, right? The one that already fast-charged your old iPhone for a year.


Apple isn't putting chargers in the iPhone 12 and iPhone 12 Pro boxes to help save the planet. It's also telling us that we already have all the chargers we need. Except most of us are using the charger that came with an old iPhone. And most of those will be 5W abominations. Others will be 18W chargers that fast-charged everything fine until today. But today, they won't fast charge your new iPhone. At least not officially.

iPhone cameras

iPhone cameras (Image credit: Rene Ritchie)

That's something that isn't entirely clear at first because Apple's own support document says that 18W chargers will fast charge just fine. Until you scroll down and read the fine print. Right at the end of the fine print, to be exact.

You need a 20W or higher power adapter to fast charge your iPhone 12.

Oh. Okay then.

So here's the situation. Any iPhone charger you have will charge your new iPhone, so long as it has a USB-C port on it. Which many won't, but we'll ignore that for a moment. But if you want to fast charge your iPhone 12 or iPhone 12 Pro, you need to buy a new 20W charger. And ditch your old one.

That seems.... less good for the environment to me.

So what kind of charging speed difference can you expect by going from an 18W charger to a 20W charger? Our very early initial testing shows that speeds over 18W are quite similar to 20W charging, but there aren't enough tests around to establish a clear difference. It's also too early to tell whether or not fast-charging not using a 20W charger may have any impact on battery life or long term performance.

Oliver Haslam

Oliver Haslam has written about Apple and the wider technology business for more than a decade with bylines on How-To Geek, PC Mag, iDownloadBlog, and many more. He has also been published in print for Macworld, including cover stories. At iMore, Oliver is involved in daily news coverage and, not being short of opinions, has been known to 'explain' those thoughts in more detail, too.

Having grown up using PCs and spending far too much money on graphics card and flashy RAM, Oliver switched to the Mac with a G5 iMac and hasn't looked back. Since then he's seen the growth of the smartphone world, backed by iPhone, and new product categories come and go. Current expertise includes iOS, macOS, streaming services, and pretty much anything that has a battery or plugs into a wall. Oliver also covers mobile gaming for iMore, with Apple Arcade a particular focus. He's been gaming since the Atari 2600 days and still struggles to comprehend the fact he can play console quality titles on his pocket computer.