Apple Watch Ultra 4 review: 5 reasons to buy, 2 to skip

The Apple Watch Ultra 4 launches with improved heart rate tracking, a new Live Rewind AI feature, longer battery life, and better step accuracy, while keeping its price unchanged. However, it retains the same display and large 49mm size as its predecessor. Apple overhauled the Ultra 4’s sensor array, claiming it is the most accurate heart tracker in any wearable, with readings taken every five minutes and HRV every 15 minutes. The Live Rewind feature buffers 15 seconds of audio for playback via double-tap, with no recordings saved. Battery life rises to 50 hours, or 45 hours in a new Max Extended workout mode. The watch’s display remains identical to the Ultra 3, with 3,000 nits brightness, lagging behind the Samsung Galaxy Watch Ultra 2’s 5,000 nits. The lack of a smaller size option also persists, as the Ultra 4 stays at 49 x 44mm, which may deter users with smaller wrists.