Apple's newly announced foldable iPhone, the iPhone Duo, does not include Face ID. Instead, the company has built Touch ID into the device's side button, giving users a familiar authentication method whether the phone is open or closed.

How Touch ID Works on iPhone Duo

According to Apple, the Touch ID sensor is integrated directly into the side button, allowing users to unlock the iPhone Duo with a fingerprint regardless of the device's fold state. This mirrors the approach Apple has long used on iPads and some standard iPhones, rather than relying on the front-facing camera system that powers Face ID on most current iPhone models.

The choice to omit Face ID may surprise longtime iPhone users accustomed to glancing at their phone to unlock it. Face ID has been the default authentication method on flagship iPhones for years, and its absence on the Duo represents a notable design tradeoff, likely driven by the engineering challenges of fitting facial recognition hardware into a foldable form factor.

Apple Watch Unlock as a Backup

Apple is carrying over a feature familiar to Mac users to soften the loss of Face ID. Just as with existing iPhones, iPhone Duo owners who also wear an Apple Watch can enable automatic unlocking, letting their paired Watch authenticate them without needing to touch the side button at all. This option effectively gives Duo users two convenient unlocking paths: a physical fingerprint sensor or a connected wearable.

Why This Matters for Foldable iPhone Buyers

For customers considering the iPhone Duo, the authentication setup is a meaningful factor in daily usability. Foldable phones often introduce compromises compared to traditional slab-style devices, and how quickly and reliably a phone unlocks affects the overall experience. By combining Touch ID with Apple Watch support, Apple appears to be aiming for a system that remains fast and convenient even without facial recognition.

Release Timing

Apple has set pre-orders for the iPhone Duo to begin at 5:00 a.m. Pacific Time on Friday, October 16. The device will become available to customers starting Friday, October 23. The Duo was unveiled alongside details about its dual-screen, foldable design, which Apple says results in the thinnest iPhone ever made when fully opened.

As more details emerge ahead of launch, prospective buyers will likely weigh the tradeoffs of the new authentication approach against the benefits of the foldable form factor itself.