Apple Watch Ultra 4 review: longer battery life, but AI features delayed
The £749 Apple Watch Ultra 4 adds longer battery life, faster charging and daytime heart rate monitoring, but Apple's promised audio intelligence features are not enabled yet.
At a glance
- The Apple Watch Ultra 4 costs from £749 and adds longer battery life, faster charging and more frequent heart rate readings.
- Testing showed 79 hours of general battery life and charging to 100% in under 90 minutes, at 10W instead of 5W.
- Apple's marquee audio intelligence features, including Siri Recap, are not enabled and are expected in late 2026.
The Apple Watch Ultra 4 is on sale from £749 (€899/$799/A$1,349), bringing longer battery life and faster charging to Apple's biggest smartwatch — but several features announced for Apple's 2026 watch lineup are not yet switched on, a Guardian review finds.
The review says the Ultra 4 is essentially the same watch as last year's model. Its body, screen, colours and design are unchanged, and it weighs about 1g more. The differences are inside, where the new S11 chip is the first meaningfully faster processor in several Apple Watch generations.
Battery and charging
In testing, battery life for general use reached 79 hours, lasting well into a third day between charges. The watch charges at 10W through its magnetic puck, up from 5W, reaching 82% in under an hour and 100% in less than 90 minutes.
Apple says the battery should manage more than 1,000 full charge cycles while holding at least 80% of its original capacity. A replacement costs £95, while damage repairs cost £539. The watch contains more than 45% recycled material, and Apple offers trade-in and free recycling.
Health and training
Upgraded rear sensors take heart rate readings every five seconds during the day, compared with every five minutes on previous generation Apple Watches, and allow daytime heart rate variability measurement rather than only overnight readings.
The Vitals app now works during the day, flagging when heart rate and HRV fall outside a user's usual baseline, which can indicate strain or sickness. A new readiness app scores recovery out of 10 and offers advice on whether the wearer is ready to exercise.
Features still to come
The Ultra 4 runs watchOS 27, the same system as Apple Watches back to the Series 9 and Ultra 2. The upgraded Siri, a new Siri Modular watch face, faster Shazam recognition and a sound recognition accessibility feature are available now.
However, the "audio intelligence" features Apple has trailed for late 2026 are not enabled. Siri Recap is intended to summarise conversations as text without recording audio or keeping full transcripts, while Live Rewind would show a transcript of the last 15 seconds of a conversation.
Verdict
The review concludes the Ultra 4 is the best smartwatch Apple makes, citing its screen, rugged design, dual-band GPS, 100-metre water resistance, satellite SOS and iPhone integration. Its drawbacks are the high price, iPhone-only support, no third-party watch faces, shorter battery life than adventure watch rivals such as the Garmin Fenix 9 (from £860), and the absence of the marquee AI features. For comparison, the Apple Watch Series 12 starts at £369 and the Watch SE 3 at £219.
Source: The Guardian Technology.
Questions and answers
- How long does the Apple Watch Ultra 4 battery last?
- In testing, it lasted 79 hours of general use, stretching well into a third day between charges. Apple says the battery should keep at least 80% of its original capacity after more than 1,000 full charge cycles.
- Is the Apple Watch Ultra 4 worth upgrading from an older model?
- The review says it is a great Apple Watch but not a significant upgrade on previous models: the design is identical to last year's and the marquee AI features have yet to arrive.
- What new AI features is Apple adding to the Apple Watch?
- Siri Recap will summarise conversations as text without recording audio or keeping full transcripts, and Live Rewind will show a transcript of the last 15 seconds of a conversation. Both are expected in late 2026.
