Apple just took the wraps off Apple Watch Ultra 4, and this is the biggest overhaul the Ultra line has had since it launched. The headline changes are all under the hood: a new Health Sensing System, a faster S11 chip, and a fresh take on how the watch reads your body throughout the day. On top of that, you get longer battery life, a smarter Health app, and Apple’s first real push into on-wrist audio intelligence.
Here’s everything that’s new, what it actually means for you, and when you can get your hands on one.
Price and Release Date
Apple Watch Ultra 4 starts at $799 and is available to pre-order today. It hits store shelves on Friday, September 18, alongside the rest of the new Apple Watch lineup. If you’re in Australia, Canada, France, Germany, India, Japan, the UAE, the UK, or the US, you can order right away, and pre-orders are open in more than 50 other countries too.
If you’d rather not pay upfront, Apple Upgrade (its leasing program through Klarna) brings the monthly cost down to as low as $24.99 over 24 months in the US.
The Most Accurate Heart Rate Sensor Apple Has Ever Shipped
This is the real story of Apple Watch Ultra 4. Apple rebuilt the entire sensing stack around what it’s calling the Health Sensing System, paired with the new S11 chip. The optical and electrical heart sensors have been redesigned from scratch, and Apple says the result is the most accurate heart rate sensing in any wearable on the market. That claim comes from a study Apple ran with over 1,000 participants, comparing its new sensor against other leading wearables.
In practical terms, larger and more power-efficient green LEDs let the watch measure your heart rate every five seconds, all day, not just during workouts. That constant stream of data makes your Exercise and Move rings noticeably more accurate, and there’s a new heart rate complication so you can glance at your current reading right from the watch face.
Heart rate variability gets the same treatment. HRV is now measured up to 24 times more often than before, and it’s broken into two separate readings: Recovery HRV, which tracks daily stress and recovery, and overall HRV, which gives you a longer view of cardiovascular health. There’s also a new daytime vitals view, so you’re not stuck waiting until the next morning to see how your body is holding up.
Readiness: A Daily Score for How Hard You Should Push
This is a genuinely new feature, and it’s one that fitness-focused users have wanted for a while. Readiness looks at your recent activity, training load, vitals, and sleep score, then hands you a single number from 0 to 10 with a plain-language recommendation: Recover, Pace Yourself, Ready, or Go For It.
It updates throughout the day, so if you crush a workout in the morning or your HRV shifts in the afternoon, your score adjusts to match. You can tap into the breakdown to see exactly what’s driving the number. Apple built the scoring model with data from its own Heart and Movement Study, working alongside exercise scientists and physicians.
Battery Life That Actually Matches the “Ultra” Name
Everyday battery life on Apple Watch Ultra 4 now stretches to up to 50 hours, and Low Power Mode pushes that to 84 hours. Charging is faster too: 15 minutes on the charger gets you up to 18 hours of extra battery.
For outdoor workouts, the new Extended Workout mode gives you up to 25 hours with full GPS and heart rate tracking, a 25 percent jump over the previous generation. If you’re doing something genuinely long, Max Extended Workout stretches that to 45 hours with GPS readings every second, which Apple points out is enough to finish a 100-mile race.
Step Tracking Gets a Rebuild
The pedometer model has been rebuilt with new machine learning algorithms and the S11 chip, giving you more accurate distance tracking on indoor walks and runs, plus more reliable step counts throughout the day. Apple is calling it the most accurate step tracking of any smartwatch. There’s also a new Steps complication so you can watch your count tick up in real time.
A Redesigned Health App With a Longevity Tab
The Health app on iPhone is getting a proper redesign later this year. A new Insights tab surfaces timely health info throughout the day, and a new Longevity tab digs into your longitudinal data, including a Health Age feature that shows how your metrics stack up against your actual age.
The app also adds movement evaluations that measure flexibility, strength, and balance using vision-based AI on iPhone combined with heart rate data from your watch. And if you want deeper lab work, you’ll be able to book blood tests covering more than 50 biomarkers for $119 through the app, at around 2,000 Quest Diagnostics locations in the US. The redesigned app rolls out later this year, starting in US English.
Audio Intelligence: Apple Watch Starts Listening (Carefully)
This is the feature set that’s going to get the most attention, and it’s a meaningful shift for what a smartwatch is supposed to do. Using the built-in microphone, the S11 chip, and Apple Intelligence models running on your paired iPhone, Apple Watch Ultra 4 introduces a batch of audio-based features:
- Sound Recognition: alerts users who are deaf or hard of hearing to sounds like sirens, doorbells, or a crying baby, even without an iPhone nearby.
- Live Rewind: double-press the Digital Crown and it shows you a text snippet of the last 15 seconds of conversation, useful for catching something you missed.
- Siri Recap: automatically generates a title and key points from a conversation after it ends, so you can review it later in the new Siri app.
- Shazam: identifies whatever song is playing around you and drops the title and artist straight into your Smart Stack.
Apple is leaning hard on privacy here. None of these features record or store audio. Processing happens inside Secure Exclave, an isolated hardware compartment on the S11 chip, and the raw audio is deleted immediately after. Live Rewind also plays an audible chime and shows a visible indicator when it’s active, even on silent, so people around you know it’s running. Everything you save syncs through the Siri app with end-to-end encryption. Live Rewind and Siri Recap arrive in beta later this year.
Siri AI Lands on Your Wrist
With watchOS 27, Apple Watch Ultra 4 gets Siri AI, the rebuilt version of Siri that understands personal context and taps into broader world knowledge. There’s a new Siri Modular watch face built specifically to make Siri easier to reach throughout the day. It’s rolling out as a beta on September 14 in English, with French, Japanese, Korean, Portuguese, and Spanish support coming in October.
What Else watchOS 27 Brings
- A dynamic app grid that surfaces five Siri-suggested apps based on what you actually use.
- A new one-handed tap gesture, so you can open a Smart Stack widget by tapping your index finger and thumb together.
- Smarter Smart Stack suggestions, like a Parked Car widget from Maps or a birthday reminder for a close contact.
- Cycle Tracking now supports perimenopause and menopause tracking.
- Workout Buddy works without your iPhone nearby, and it’s now available in Spanish alongside English.
Colors, Bands, and the Hermès Edition
Apple Watch Ultra 4 comes in natural and black titanium. The band lineup gets new colorways for fall: Trail Loop in dark umber, sand, and burgundy, Alpine Loop in desert, dark olive, and burgundy, and Ocean Band now made from a translucent silicone in gray, kelp, and black.
Apple Watch Hermès Ultra 4 gets its own upgrades too, including a new Grand H titanium band with a built-in extension so it fits over a wetsuit, and a new Fathom and Wonder watch face that lets you explore an animated illustration of the ocean depths using the Digital Crown.
Built With Recycled Materials
Apple Watch Ultra 4 is made with 45 percent recycled material overall, including a fully recycled titanium case and fully recycled cobalt in the battery. Manufacturing runs entirely on renewable electricity, and the packaging is 100 percent fiber-based.
Should You Upgrade?
If you’re coming from Apple Watch Ultra 2 or later, this is the first Ultra refresh in a while that’s worth paying attention to. The heart rate accuracy claims, the readiness score, and the jump to 45-hour battery life on long outdoor sessions are real, tangible upgrades for anyone who actually uses the “Ultra” part of this watch. Audio Intelligence is more of a bonus than a reason to buy on its own, especially since Live Rewind and Siri Recap are still in beta.
Either way, pre-orders are live now, and the watch starts shipping September 18.
