Apple Watch Ultra 4 review: longer battery life but still awaiting new features

As the Ultra enters its fourth year as Apple’s biggest and beefiest smartwatch it gets the best kind of spec upgrade – longer battery life – while waiting for something potentially more transformative.

That’s because several of the key features announced as part of Apple’s new smartwatch lineup for 2026 have yet to be enabled, awaiting updates towards the end of this year. That leaves the £749 (€899/$799/A$1,349) Apple Watch Ultra 4 the top dog, but basically the same as last year’s model.

The Ultra 4’s body, screen, colours and design are identical to the previous versions. It weighs about 1g more, but the bigger changes are on the back and inside.

Upgraded sensors on the back of the watch take heart rate (HR) readings every five seconds during the day, up from every five minutes on previous generation Apple Watches. They also enable the measurement of your heart rate variability (HRV) during the day, not only at night, which feeds into some new recovery metrics.

The Ultra 4 is the first Apple Watch in several generations to get a meaningfully faster chip with the new S11. The battery life for general use in my testing now stretches to 79 hours, too, meaning the watch lasted well into its third day between charges. Most will be able to charge it every third morning, or less if you use the low power modes, although that is far behind the week-plus stamina of top adventure watch rivals.

The new watch charges at 10W with its little magnetic puck, up from 5W of previous generations, and reached 82% in under an hour and 100% in less than 90 minutes.

Specifications

• Case size: 49 x 44mm

• Case thickness: 12mm

• Weight: 63g

• Processor: S11

• Storage: 64GB

• Operating system: watchOS 27

• Water resistance: 100 metres (10ATM)

• Connectivity: Bluetooth 5.3, wifi 4, 5G RedCap/4G, UWB

• Sensors: HR, ECG, spO2, temp, depth, dual-band GPS, compass, altimeter

Vitals and readiness

The Apple Watch features some of the most comprehensive health tracking available on your wrist, which on the Ultra includes extremely accurate dual-band GPS tracking for exercise. The more frequent HR and HRV measurements enable a few new features for the Ultra 4. The Vitals app, which monitors your stats overnight, now works during the day giving you an assessment of your general health. It can let you know when your HR and HRV are outside your usual baseline, indicating strain or sickness that might be on the way.

The new readiness app adds a popular feature from sports watches, which looks at your activity, vitals and sleep and works out whether you have properly recovered from strenuous exercise or stressful days. It gives you a score out of 10 and some advice on how ready you are for exercise, which can be a useful tool for training for a race or goal.

watchOS 27 and AI

The Ultra 4 runs watchOS 27, just like Apple Watches back to the Series 9 and Ultra 2, which includes Apple’s new Siri and improved AI tools, some of which are available now, while other exclusive features are awaiting updates planned for later this year.

The upgraded Siri is available to talk to and behaves very similarly to that on a modern iPhone, including the Siri app for reviewing previous interactions. The new Siri Modular watch face features the top timely widget, which has been surprisingly useful. It shows simple things such as the timer when you have one running, or the weather when it starts raining. It also puts your vitals front and centre in the morning, or your calendar if you have an upcoming event, replacing the need for multiple complications.

Shazam music recognition is now significantly faster, while the sound recognition accessibility feature, which listens out for certain sounds, such as a fire alarm, doorbell, car horn or baby crying, and sends an alert to your wrist could be very useful.

But the marquee “audio intelligence” features that could be transformative and controversial are not yet enabled, being expected in “late 2026”. Siri Recap promises to transcribe conversations all day before delivering them as an AI summary. It doesn’t record audio or keep full transcripts, just the text summaries, but the Live Rewind feature can show you a transcript of the last 15 seconds of a conversation so you can see what you missed.

Sustainability

Apple says the battery should last more than 1,000 full charge cycles with at least 80% of its original capacity and can be replaced for £95. Damage repairs cost £539.

The watch contains more than 45% recycled material, which is broken down in its environmental impact report. Apple offers trade-in and free recycling for devices.

Price

The Apple Watch Ultra 4 comes in a choice of two colours and multiple bands costing from £749 (€899/$799/A$1,349).

For comparison, the Apple Watch Series 12 costs from £369, the Watch SE 3 costs £219 and the Garmin Fenix 9 costs from £860.

Verdict

The Ultra 4 is the best smartwatch Apple makes. It has a great screen, rugged looks and all the trappings of other Apple Watches, including Apple Pay, comprehensive health tracking and full integration with an iPhone.

The faster charging and longer battery life are welcome, lasting about six hours more for general use than previous versions in testing. The more frequent heart rate readings and daytime heart rate variability monitoring are additive rather than revolutionary. The readiness and recovery monitoring add to the existing suite of training tools to close the gap to top-tier sports watches from Garmin and others.

Upgraded Siri is more useful on your wrist, and the new Siri Modular watch face was a surprisingly good addition. But the new audio intelligence features are not here yet.

That makes the Ultra 4 a great Apple Watch, just not a significant upgrade on those that came before.

Pros: great screen, rugged yet sophisticated design, hands-free gestures, three-plus-day battery life, 4G/5G and satellite SOS/messaging, comprehensive health tracking, great activity tracking with dual-band GPS, recovery/readiness tracking, better Siri, extra action button, 100-metre water resistance and 40-metre dive-ready, long software support.

Cons: no big upgrade on previous model, very expensive, only works with an iPhone, no third-party watch faces, shorter battery life than adventure watch rivals, marquee AI features not yet available.