Apple Watch Ultra 4 Review (UK): Longer Battery, Smarter Health Tracking
Quick verdict
The Apple Watch Ultra 4 is Apple's toughest, longest-lasting smartwatch. It keeps the Ultra 3's 49mm titanium design and £749 price, but adds up to 50 hours of battery life, faster charging and a redesigned Health Sensing System with a daily readiness score. Independent reviewers call it the best Ultra yet, though Ultra 3 owners don't need to rush to upgrade.
Check current price on Amazon UKApple announced the Apple Watch Ultra 4 at its September 2026 event, with pre-orders from 9 September and UK availability from 18 September. It replaces the Apple Watch Ultra 3, which we previously covered. From the outside little has changed: it's still a 49mm titanium watch with the Action button, a flat sapphire display and satellite connectivity. The upgrades are inside, with the new S11 chip, a bigger step up in battery life and much more frequent heart rate tracking.
Who is it for?
The Ultra 4 suits trail runners, hikers, cyclists, swimmers and divers, and anyone who wants the longest battery life and most safety features available on an Apple Watch. WIRED points out that the cheaper Apple Watch Series 12 now shares many of the Ultra 4's health and safety features. The Ultra's biggest advantages are its multi-day battery, the Action button and satellite messaging, so it makes most sense for people who actually spend time off the grid. If you want something slimmer and lighter for everyday wear, look at the Series 12 instead.
Key specs
- Case: 49 x 44 x 12mm Grade 5 titanium, natural or black, 63.0g (natural) or 63.1g (black). Fits 130–210mm wrists
- Display: Always-On Retina display with wide-angle OLEDs and LTPO3, 422 x 514 pixels, flat sapphire crystal, up to 3,000 nits and as low as 1 nit
- Chip: Apple S11 with 4-core Neural Engine, 64GB storage
- Health: new Health Sensing System with electrical and optical heart sensors, background heart rate every five seconds, HRV as often as every five minutes, readiness score, ECG, blood oxygen, temperature sensing, sleep score, and sleep apnoea and hypertension notifications
- Battery: up to 50 hours of normal use, 84 hours in Low Power Mode, 18 hours of outdoor workout tracking and 45 hours in Max Extended Workout. 15 minutes of fast charging gives up to 18 hours
- Connectivity: 5G (RedCap) and LTE, satellite communications for Emergency SOS and Find My, precision dual-frequency GPS, Wi-Fi, Bluetooth 5.3, second-generation Ultra Wideband
- Durability: WR100 water resistance, EN13319 recreational scuba diving to 40m, IP6X dust resistance, tested to MIL-STD 810H
- Compatibility: requires iPhone 11 or later with iOS 27 or later
What's new over the Ultra 3
Battery life is the headline. Apple quotes up to 50 hours of normal use and 84 hours in Low Power Mode, up from 42 and 72 hours on the Ultra 3. Fast charging is quicker too: 15 minutes now gives up to 18 hours of use, compared with 12 hours on the Ultra 3. Gizmodo notes you get that faster charging with the charger in the box, though it looks exactly like the old one.
The other big change is the Health Sensing System, shared with the Series 12. Apple says it takes background heart rate readings 60 times more often than the Ultra 3 and HRV readings 24 times more often. That feeds a new readiness score, which uses your recent activity, vitals and sleep to suggest whether to train hard or rest. Outside found the score matched how it felt, though it sometimes didn't appear until after a morning run.
Siri AI and Audio Intelligence
The Ultra 4 supports Apple's new Siri AI, which Apple says is rolling out in English. It also gets Audio Intelligence features, including Live Rewind, Siri Recap, Sound Recognition and faster Shazam, which are exclusive to the Ultra 4 and Series 12. Live Rewind and Siri Recap arrive in beta in late 2026 and need an Apple Intelligence-capable iPhone 16 or later, so don't buy the watch for those features alone.
What reviewers say
Tom's Guide ran 22 miles with the Ultra 4 against a chest strap and called it the best Apple Watch Ultra yet, praising the continuous heart rate sensing and recovery insights. It would still like a smaller size option. WIRED liked the battery and health upgrades but felt the gap to the Series 12 keeps shrinking. Gizmodo said the extra battery life and easy-to-read screen won it over after two and a half weeks of testing.
Pros and cons
Pros
- Up to 50 hours of battery, 84 in Low Power Mode
- Faster charging: 18 hours from 15 minutes
- New Health Sensing System and readiness score
- Satellite SOS and Find My, plus 5G
- WR100, IP6X and dive-rated to 40m
- Same £749 launch price as the Ultra 3
Cons
- Expensive
- One 49mm size only, bulky on smaller wrists
- Design and display unchanged from the Ultra 3
- Some AI features not arriving until late 2026
- Works with iPhone only
UK price
The Apple Watch Ultra 4 costs from £749 at Apple UK, and Amazon UK listed it at £749 when we checked on 4 October 2026. Some straps cost more. The Ultra 3 is now the previous model and is often cheaper, so it's worth comparing both. Prices change often, so check the current price on Amazon UK before you buy.
Verdict
The Apple Watch Ultra 4 is the most capable smartwatch you can pair with an iPhone. Reviewers agree it's an incremental update rather than a reinvention, but more than two days of battery, faster charging and better heart tracking make it the Ultra to buy in 2026. Owners of an older Ultra or a Series watch with poor battery life will notice the biggest difference.
FAQs
How much is the Apple Watch Ultra 4 in the UK?
Apple sells the Apple Watch Ultra 4 from £749 at apple.com/uk, the same launch price as the Ultra 3. Amazon UK listed it at £749 when we checked on 4 October 2026. Some straps, such as the Titanium Milanese Loop, cost more.
How long does the Apple Watch Ultra 4 battery last?
Apple quotes up to 50 hours of normal use and up to 84 hours in Low Power Mode, up from 42 and 72 hours on the Ultra 3. For workouts, Apple quotes up to 18 hours of outdoor workout tracking, 25 hours in Extended Workout and 45 hours in Max Extended Workout. Fifteen minutes of fast charging gives up to 18 hours of normal use.
Should I upgrade from the Apple Watch Ultra 3?
Probably not, unless you want the longer battery life, the new Health Sensing System or the Audio Intelligence features. Tom's Guide wasn't sure it would upgrade from an Ultra 3, but recommends the Ultra 4 to owners of older Ultra models and anyone who wants longer battery life.
Which iPhone do I need for the Apple Watch Ultra 4?
Apple says it needs an iPhone 11 or later, including iPhone SE (2nd generation or later), running iOS 27 or later. Some Audio Intelligence features, such as Live Rewind and Siri Recap, need an Apple Intelligence-capable iPhone 16 or later (excluding iPhone 16e) and arrive in beta in late 2026.
How we researched this review: we compiled this guide from Apple's official UK specifications and pricing (apple.com/uk) and independent hands-on reviews from Tom's Guide, WIRED, Gizmodo and Outside, with launch pricing and dates confirmed by TechRadar. We have not tested this product ourselves. The Apple Watch Ultra 4 replaces the Apple Watch Ultra 3 we previously covered.