You need to have an iPhone 12 or newer to use Face ID with a mask

A new feature in iOS 15.4 and iPadOS 15.4 for using Face ID while wearing a mask requires at least the iPhone 12: it won’t work on the iPhone 11 and the iPhone X or older.

  • iOS 15.4 and iPadOS 15.4 bring a new ability to unlock your iPhone or iPad with Face ID while wearing a mask, even if you’re not wearing an Apple Watch for authentication
  • The new feature seems to require the iPhone 12’s Apple A14 chip or later
  • It doesn’t currently work on the iPhone 11 series and older models
  • Regular Face ID works on the iPhone X and newer

iOS 15.4’s Face ID with a mask requires iPhone 12 or newer

Apple yesterday seeded the first betas of what would become the iOS 15.4 and iPadOS 15.4 software updates to its registered developers and beta testers. Among other goodies, the updates bring a tweak to the Face ID feature which can now authenticate you while wearing a mask, even if you’re not wearing an Apple Watch to add an extra layer of security. It’s a much-needed, albeit overdue improvement that makes Face ID more convenient in the pandemic.

Too bad you’ll probably need a newer iPhone model to use this feature.

MacRumors notes that people are reporting that using Face ID with a mask only works on the iPhone 12 series or later. In other words, you’ll need to use an iPhone 12 mini, iPhone 12, iPhone 12 Pro, iPhone 12 Pro Max, iPhone 13 mini, iPhone 13, iPhone 13 Pro or iPhone 13 Pro Max to use the new “Face ID with a Mask” option.

The site clarifies:

If you have an iPhone 11 or earlier, you will not see the Face ID with a Mask setup screen when updating to iOS 15.4, nor will you have the option to toggle it on in the Settings app.

It’s puzzling why unlocking an iPhone with Face ID while wearing a mask is limited to the iPhone 12 or newer. It’s even stranger remembering that the regular Face ID feature does work on older iPhones as far back as the iPhone X, which came out in 2017.

Why doesn’t this feature work on iPhone 11 and older?

A still from Apples iPhone X ad showing a woman by the poolside using Face ID to unlock her phone

Perhaps support for older devices will be implemented in subsequent betas. A more probable explanation is that the feature requires additional computations to scan the area around the eyes. Read: How to set up an alternate appearance using Face ID

From the feature’s description in iOS 15.4:

Face ID is most accurate when it’s set up for full-face recognition only. To use Face ID while wearing a mask, iPhone can recognize the unique features around the eye area to authenticate. You must be looking at your iPhone to use Face ID while wearing a mask.

Face ID is a machine learning feature that makes heavy use of Apple’s dedicated neural network hardware, dubbed Neural engine. The Neural engine in the Apple A14 chip powering the iPhone 12 series has 16 cores and can perform 11 trillion operations per second. The Neural engine in the Apple A13 chip from the previous iPhone model, the iPhone 11, has half the cores (eight) and can perform more than five trillion operations per second, approximately half as much as the A14’s Neural engine.

It’s this significant performance gap between the Neural engine in the iPhone 12 versus older iPhones that could explain why Apple limited using Face ID while wearing a mask in iOS 15.4 to the iPhone 12 or newer. Another viable explanation: using Face ID while wearing a mask may require updated Face ID hardware available in the latest iPhones.

How to set up Face ID with a mask

To authenticate with Face ID while wearing a face mask, without having to wear an Apple Watch, turn on the option labeled “Use Face ID With a Mask” in your Face ID settings.

  1. Open the Settings app on your iPhone with iOS 15.4 or later
  2. Touch “Face ID & Passcode” in the root list
  3. Slide the switch labeled “Use Face ID With a Mask” to the ON position

You may also be asked to configure this feature so that it works with glasses.

Here’s Apple’s description:

Using Face ID while wearing a mask works best when it’s set up to recognize each pair of glasses you wear regularly. Face ID with a mask doesn’t support sunglasses.

People who own an Apple Watch can use the “Unlock with Apple Watch” feature for more convenient access to Face ID while wearing a mask than this new option in iOS 15.4. An unlocked Apple Watch worn on one’s wrist is used to aid Face ID authentication, acting as an extra layer of security. Unlocking iPhone with Apple Watch (and regular Face ID) works on all Face ID-enabled iPhones from the iPhone X onward.