Apple Watch Ultra 4 review: An end-to-end health ecosystem

Apple's new Health Sensing System for Apple Watch Ultra 4 means more accurate and more frequent health metric tracking. It feels like the peak offering of a device before a necessary complete redesign.

Nearly every improvement made to Apple Watch Ultra 4 relates to health, fitness, and the ability to track those metrics. Even the longer battery life was pitched as a way to track metrics over a longer period of time.

Tim Cook may have stepped down as CEO before Apple Watch Ultra 4 was revealed, but it and the Apple Watch Series 12 are clear realizations of his vision. Apple Watch is a health-focused wearable that aims to improve the wearer's life, and perhaps even save them in emergency situations.

Out of all of Apple's products, the Apple Watch is perhaps the most mature with very little wiggle room, even when compared to the Apple TV — there just isn't enough space. That is clear given that even the Apple Watch Ultra 4 gained a gram in weight thanks to the new sensor system.

The Apple Watch Ultra line appears to be in an even more awkward position compared to the standard "Series" line. It has consistently received all of the updates brought to models like Apple Watch Series 12 (on sale now), but nothing "Ultra" has been added or upgraded since the original model's launch.

As I pointed out in my Apple Watch Ultra 3 review, it's still the larger, high-end watch with the most sensors and ruggedness. However, Apple seems stumped on how to iterate on the premium Apple Watch beyond keeping it in lock step with the rest of the lineup.

That said, the 2026 model at least is a significant step forward. Here's what Apple Watch Ultra 4 offers.

Apple Watch Ultra 4 review: Design

When you're looking at Apple Watch Ultra 4 on someone's wrist, you'll never guess which generation it is from design alone. Apple has stuck with the same design since the original launched, though the black option did arrive as a change in gen 2.

Flip it on its back and you'll see a significant difference thanks to the new Health Sensing System. Apple has replaced the sensor stack with updated components for more frequent and more accurate readings.

The electrodes are larger, which surround the photo diodes where green LEDs are shown through to collect data. This all fits in the Apple Watch, though there has been a weight increase of about 1.4 grams.

It's such a small change that I haven't noticed a difference.

The display is identical across generations, you're getting the same 100m dive spec, and it is still a titanium case with orange accents. I do think Apple could have made a statement with a new case color or design tweak, but that wasn't for this year.

Apple Watch Ultra 4 review: Features

Much of what was introduced in Apple Watch Ultra 4 and Apple Watch Series 12 is tied to the updated Health app coming in iOS 27.2. I've tested the Watch with and without this update, but I won't spend too much time on the app itself here.

All of the metrics that matter most on Apple Watch saw a boost with the new system. These upgrades come at no loss of battery life, and even then, Apple says the battery life has increased in the latest generation.

Here is every new feature for Apple Watch Ultra 4:

• Health Sensing System
• Second-generation electrical heart sensor
• Always-on optical heart sensor
• Improved step tracking
• Recovery HRV
• High-frequency background heart rate tracking
• HRV in the Vitals app
• Audio Intelligence
• Single-tap gesture

There's also the new Readiness app, but I've not had enough nights of data collection for it to show anything just yet. It gathers data over a week, and as this is published, it has been a week since getting the device. I'll discuss Readiness when I write more about the new Health app, which deserves its own full breakdown.

All of these new sensors add up to a new health-forward platform that should excite anyone that likes putting data in databases. Your heart rate is read every five seconds and HRV data is collected every five minutes.

Heart Rate Variability has become a popular way to measure a person's overall health, mostly due to products like the Whoop health band. Apple already collected this data, but it is putting it front and center with the Apple Watch Ultra 4.

I personally don't care about any individual health metric, but the idea of getting more data that's more accurate is appealing to me. I want my new Apple Health app with Apple Intelligence to have every bit it can to help with my health journey.

I don't feel the need to detail every Apple Watch Ultra feature, as they should be fairly well-known by now. It's a rugged smartwatch that can withstand extreme conditions, has a siren for emergencies, can make emergency calls via satellite, and has a much longer battery life than standard Apple Watches.

Apple Watch Ultra 4 has identical wireless specs with Wi-Fi 4, Bluetooth 5.3, and 5G.

The Apple Watch Ultra 3 was my first Apple Watch Ultra, so I broke down the smaller details in that review. That's the thing — Apple's Ultra updates lack new "Ultra" features, so rehashing identical feature lists seems redundant.

The base feature set exclusive to Apple Watch Ultra hasn't changed since the original model beyond satellite connectivity. I'm glad Apple has added the S11 and the benefits provided by that chipset, but we're not seeing anything else.

That chipset is what enables many of the upgrades without sacrificing battery life. The S11 has a neural engine derived from the A20 Pro used in iPhone 18 Pro (check deals), which enables new AI features.

A boost in battery life

That battery life is particularly impressive with Apple Watch Ultra 4, as it gained about 8 hours in regular use. Previously, Apple Watch Ultra could last about 42 hours without a charge, but now it's 50 hours.

That takes it well over the two-day without-charging threshold. For most people, that should mean taking it off to charge while showering should occur at some point in that 50 hours.

And yes, charging in the shower is more than enough time to top off the battery. Get 80% battery in about 45 minutes or fast charge for just 15 minutes for 18 additional hours of use.

I take a long shower and don't rush to put the watch back on, so that's more than enough time to get the battery somewhere near 100% every day or two. It may be the "rugged" or "adventurer" Apple Watch, but I am willing to bet much of the sales of Apple Watch Ultra comes from people seeking longer battery life.

That said, it is quite the smartwatch for athletes. Apple says that people running a 100-mile race have enough battery life to log the entire race in workout tracking mode.

There's not much more lengthy or demanding than that in sports.

Using Apple Watch Ultra 4

You know the drill, this is an Apple Watch. It may have a more rugged case and the addition of an Action button, but it's a nearly identical experience in most use cases to standard models.

I was worried about Apple Watch Ultra having too big a case or being awkwardly large or heavy on my arm. Thankfully, I was wrong on all counts.

Apple's lack of significant upgrades year-over-year in several Apple Watch cycles left me believing that 2026 would be the year I could skip an update. If anything, the update this year is far mor significant than the 2025 model, which of course meant another upgrade for me.

I'm not an athlete, I don't climb mountains in sub-zero climates, and I don't dive deep into the ocean with a scuba tank. Nope, I'm your average, could be in better shape, work from home, desk worker.

The longer battery life, larger display, Action button, titanium build, and additional features are all attractive and useful to me. It is why I went Ultra the moment we got a black color and new chip generation, and I expect that's the case for many people.

I'm sure there's a better use of the Action button, but I've kept it mapped to opening Workouts. It lets me quickly start a walking workout each day, which is something I'm trying to do regularly.

The new Siri Modular watch face is nice. I've begun using it for my personal watch face, while Wayfinder remains excellent for my work face.

I've already begun incorporating the new Apple Health app into my daily routine. I check it for health insights, trends, and am making changes to my life to try and meet certain goals.

This review isn't the place to get into all of that, but I do think the new hardware capabilities and the Apple Health upgrades will be excellent selling points. It's not that I don't know how to be healthy or eat right, but having these apps and devices laying bare my exact health metrics and how to improve them, it's hard to ignore.

More on that soon.

Absent Audio Intelligence

I really wanted to write about these controversial new AI features introduced in Apple Watch Ultra 4. Unfortunately, they're not here yet, not even in beta.

One neat feature enabled by the more powerful chipset is the new near-instant Shazam music recognition. I can raise my wrist, double tap to open the Smart Stack, and the first item in my stack is usually Shazam, which quickly shows whatever song is playing around me.

The single tap gesture works when selecting items in Smart Stack or clicking buttons shown on the display. It doesn't always work, but I appreciate the new gesture.

Anyway, Siri AI is fast and accessible on Apple Watch Ultra 4. I asked several world knowledge questions, some personal based on data from Messages, and both worked great.

It's a very similar experience to what you'll find on iPhone. I asked what was for dinner, which is in my Calendar, then I asked if it was a healthy meal.

Then, I asked when my friend's birthday is and what gifts it would recommend. While the recommendations were a bit silly, I appreciate that it was able to do these queries at all, let alone on an Apple Watch.

Audio Intelligence is going to be quite the interesting feature to test. I've had mixed reactions from various people in my life that I've described it to.

It's what you would expect — some call out the potential utility while others see the obvious potential for abuses. We won't know what this will and won't enable until it can be tested.

So, as much as I'd like to have something to say about the feature, that'll have to wait for another day. I do believe what Apple has on offer in the 2026 Apple Watch generation should make any AI wearable company at least a little nervous.

Apple's new health mandate

Increasingly, it feels like Apple's messaging around Apple Watch is "if you don't wear Apple Watch, you could die." It's a terrific if terrifying prospect for many reasons.

Apple Watch Ultra 4 lasts longer than ever when worn, so you don't even need to charge it before sleeping most nights. Every bit of data will help you meet your goals, so every second without an Apple Watch is a missed opportunity to prove to the Health app how well you're doing.

I know that some people will find that disturbing, while others will find it enticing. I personally can appreciate the motivation that logging, aggregating, and viewing data can bring, with the added bonus of it not being sold, so bring it on.

Apple Watch Ultra 4 isn't necessary to take advantage of the upcoming Apple Health app updates, but it'll provide a more accurate, more constant series of metrics. I can easily highly recommend the Apple Watch Ultra 4 to anyone that cares about health, fitness, or wearable AI tools.

Apple Watch Ultra 4 - Pros

• Exceeding two days of battery on a single charge is amazing
• Health Sensing System means more accurate, more frequent data
• S11 provides a more native-feeling Siri AI experience
• Rugged, durable, and includes the useful Action button

Apple Watch Ultra 4 - Cons

• Apple still hasn't bothered with new "Ultra" features
• The overall Apple Watch experience doesn't differ much from the regular Apple Watch beyond what improved specs bring
• Audio Intelligence isn't available to test and remains quite controversial as a feature

Review: 4 out of 5

If you're wondering exactly how an Apple Watch Ultra might get a perfect score, it would be a redesign in addition to useful new features making Apple Watch Ultra more than just an Apple Watch with titanium and a larger screen. We've got some great health upgrades, AI features, and more battery life, but you wouldn't know, and can't tell that it's new.

Design isn't everything though. Apple needs to give Apple Watch Ultra users new Ultra-focused features as well, which is the main issue.

Otherwise, this is a great Apple Watch upgrade and I can easily recommend one, even if you're coming from the previous model. It just needs more in 2026.

Where to buy the Apple Watch Ultra 4 at a discount

The Apple Watch Ultra 4 is on sale now, with prices dipping to as low as $779.99 at Amazon at press time.

You can compare the latest Apple Watch Ultra 4 prices and deals across popular retailers in our Price Guide as seasonal sales pop up.

Limited inventory remains on the last-generation Ultra 3, with closeout deals at your fingertips in our Apple Watch Ultra 3 Price Guide.