Apple Watch Ultra 4 Lasts Fifty Hours and Still Has Room for a Race

Apple kept the familiar 49-millimeter Grade 5 titanium case for Watch Ultra 4, offered in natural or black, and built that shell with 100 percent recycled titanium. Dimensions stay 49 by 44 by 12 millimeters. Weight ticks up a gram or so to about 63 grams. Sapphire covers the same Always-On LTPO3 wide-angle OLED, 422 by 514 pixels, peaking at 3,000 nits and dimming to 1 nit. Action button, Digital Crown, and side button remain where they were. Dual speakers still push an 86-decibel siren. A three-microphone array handles wind and conversation. Water resistance holds at 100 meters with recreational scuba to 40 meters, IP6X dust rating, and MIL-STD-810H testing. Oceanic+ and similar apps still turn the watch into a dive computer with depth, water temperature, and entry-exit GPS marks.

Everyday use duration has increased to 50 hours, up from 42 hours on the Ultra 3. Low Power Mode can also last up to 84 hours. You can now complete a full GPS and heart-rate workout outside for around 18 hours, and if you choose the new Extended Workout mode, that figure increases to 25 hours. Then there’s Max Extended Workout, which is built for extended trail days and 100-mile events, allowing you to go for an outside run, walk, or hike for up to 45 hours while still getting your GPS fix every second (even if some other functions have to be turned down to save battery life). Fifteen minutes on the magnetic charger adds an extra 18 hours to your watch, or you can charge it from zero to 80 percent in 45 minutes. Apple put its new watch through a demanding 50-hour test, including hundreds of time checks, notifications, two-hour workouts with music streaming via Bluetooth, sleep tracking, and a combination of cellular and iPhone Bluetooth.

Apple’s S11 is powered by a 64-bit dual-core processor that includes a four-core Neural Engine and 64GB of storage. This all feeds into the new Health Sensing System, which Apple claims is the most accurate heart-rate monitoring system available, based on their own analysis of over 1,000 people compared to some of the best-selling watches. The new green LEDs can take a heart rate reading every five seconds throughout the day, and heart-rate variability is measured much more frequently (24 times as often), which is divided into a Recovery HRV compared to your personal baseline and another view of your overall HRV picture

A fresh Readiness score appears daily, ranging from 0 to 10, based on recent activity, training load, vitals, and how well you slept, with options to Recover, Pace Yourself, Ready to Go, or Go For It, and it all updates throughout the day as your situation changes. Daytime vitals are displayed alongside those taken overnight, allowing you to identify any changes before going to bed. Of course, the rest of the standard Health features remain: ECG, blood oxygen, hypertension and irregular-rhythm alerts, sleep score, fall and crash detection, and don’t forget that Cycle Tracking now includes perimenopause and menopause for those over 40. A revamped Health app will be available in 2026, with a new Insights page that provides a daily overview and a Longevity tab that displays your Health Age. In addition, you can estimate your VO2 Max using your watch, AirPods Pro 3, or another heart-rate strap.

According to Apple, the GPS remains the most accurate on-device sports-watch GPS, and it has been tested in harsh metropolitan running and walking conditions. Apple has also improved step counting with a new machine-learning model, and it now ranks first among smartwatches in a 1,000-step video-validated test. You may also place a live Steps complication directly on your watch face. Workout Buddy may now complete a session with you without requiring your iPhone, as long as there is Wi-Fi or cellular coverage, and Spanish is now available alongside English. Not to mention that Backtrack, Check In, and satellite emergency SMS, SOS, and 5G continue to function when cell towers are unavailable, and if someone prefers to remain silent, they can still manage their watch with a wrist flick, single tap, or double tap.

WatchOS 27 will finally be available on September 14, and it’s been a long time coming. Apple has unveiled its new operating system, which combines Siri AI into compatible watches when coupled with an Apple Intelligence iPhone. When you glance at your watch, you’ll be able to tap into Siri’s vast reservoir of knowledge, mixing personal context from your email, calendar, and chats with all of the broader world information that Siri knows. You can even maintain a conversation with Siri using a dedicated Siri app on your watch, and the Siri Modular face, of course, allows you to access that assistant in under two seconds. It is now only available in English; however, more languages will be added in October. Roll the clock ahead to 2026, and you’ll be able to participate in the Audio Intelligence beta, which will be available on Ultra 4 and Series 12.

Before that, even if you don’t have an Ultra watch, your watch will be able to alert you to a doorbell, alarm, siren, or baby cry when your iPhone is gone, which is quite useful. Live Rewind will also begin in September. Double tap the Digital Crown to convert the past 15 seconds of a conversation into a text snippet, which you can subsequently ask Siri about or store to your watch. Meanwhile, Siri Recap summarizes a chat in a few short phrases. Shazam now also works faster.

Now all you have to do is go to your Smart Stack and ask it to identify a tune. Apple maintains that it never records raw audio; instead, it processes the sound using a hardware-isolated Secure Exclave before deleting it. Oh, and the microphone and chime indications are still there even when your watch is set to silence. Most of these capabilities begin in English and will initially skip the EU; you’ll also need a recent Apple Intelligence iPhone, and you should keep an eye on things because there are daily server constraints. Surprisingly, these communication tools will require opt-in, feature by feature.

The new Ultra 4 stays priced at $799, with a new variety of Hermès Grand H band options, including a titanium strap with an extender that allows it to fit over a wetsuit. Apple also states that 45% of all materials used are recycled, and that all cobalt in the battery is 100% recycled. Preorders began alongside the September 9 announcement, and the first watches will be delivered on September 18. Ultra 3 owners will be familiar with the casing design, 3,000-nit panel, dive rating, and satellite safety net because they already have them.