The Apple Watch Series 12 looks familiar from the outside, but the changes to the internal components mark the beginning of a new era for wearable devices, particularly in health tracking and the highly anticipated AI features on the wrist.

Two key upgrades stand out: the new S11 chip, which delivers a faster CPU, GPU, and Neural Engine, along with a secure, isolated environment for microphone data processing; and a redesigned health sensor array with larger electrodes, redesigned photodiodes, and more efficient optical LEDs.

These sensors enable true continuous heart rate monitoring, taking a measurement approximately every five seconds at rest and during activity, rather than sampling every five minutes when not exercising. In tests using a chest strap, the Series 12 remained within a range of approximately five beats per minute of the Polar H10.