Apple's priciest watch now lasts three days, but big features wait

Apple's Watch Ultra 4 costs $799 and lasted 79 hours on one charge in The Guardian's testing. That is well into a third day. The catch is that the features Apple is most excited about, built around audio and AI, have not arrived yet. For now, the watch looks and feels the same as last year's model.

What changed

The body, screen, colors and design are identical to earlier versions. The watch weighs about 1 gram more. The real changes are on the back and inside.

• A new chip, the S11, is the first meaningfully faster one in several Apple Watch generations.
• Heart rate is checked every five seconds during the day, up from every five minutes on older models.
• Heart rate variability, the small timing changes between beats, is now measured during the day, not only at night.
• Charging is faster at 10W, up from 5W. It hit 82% in under an hour and 100% in less than 90 minutes.

The extra readings power two health tools. The Vitals app now works during the day and can flag when your numbers drift from your usual baseline, which may point to strain or illness. A new readiness app looks at your activity, vitals and sleep and gives a score out of 10 for how recovered you are.

What is not here yet

Apple's headline audio features are expected in late 2026 and are not turned on. Siri Recap would transcribe conversations through the day and give you an AI summary. Apple says it does not record audio or keep full transcripts, only the text summaries. A related feature, Live Rewind, shows a transcript of the last 15 seconds of a conversation. The reviewer called these features potentially transformative and controversial.

Other software changes are already here. The new Siri behaves much like Siri on a modern iPhone. A new watch face shows timely items, such as a running timer or rain in the forecast. Shazam is faster, and the sound alert feature can notify you of a fire alarm, doorbell, car horn or crying baby. The software, watchOS 27, also runs on watches back to the Series 9 and Ultra 2.

How it compares

Three days is good for Apple but short next to top adventure watches, which last a week or more. Prices quoted in the review are in British pounds: the Series 12 starts at £369, the Watch SE 3 at £219 and the Garmin Fenix 9 at £860. The Ultra 4 starts at £749, or $799 in the US.

What to do

Owners of last year's Ultra have little reason to rush. Better battery life and more frequent heart readings are real gains, but the biggest promised features are still weeks away. Anyone buying their first Ultra gets the best watch Apple makes, with updates still to come.