Apple Watch Series 12 reviews like the new heart sensor and Readiness score, not the battery

Apple kept the Series 12’s starting price at $399, and the reviews say the money goes to health sensing rather than to a bigger battery. Wareable lists $399 for the 42mm aluminium GPS model, the same as the Series 11, and $449 for the 46mm. Across three reviews, the new heart sensor and the Readiness score earn praise. Battery life and some early reliability issues do not.

This roundup uses Wareable, Macworld and iPhone in Canada. Their experiences with battery and bugs differ enough that the disagreements are the most useful part.

What the reviewers like

The redesigned Health Sensing System is the main upgrade. iPhone in Canada describes larger green LEDs, rearranged photodiodes and larger ECG electrodes, with background heart rate sampled every five seconds, about 60 times more often than the Series 11. Wareable says the sensor matched a chest strap closely on averages in its testing, though it logged some dropouts and sometimes lagged when effort changed. It also criticises Apple’s own accuracy study for not counting missing readings.

Readiness is the new software feature all three discuss. It is a 0 to 10 score with four labels: Recover, Pace Yourself, Ready and Go For It. Macworld finds it useful but notes it needs at least seven nights of wear before it shows a score. Wareable calls it competent and easy to read but less in-depth than Whoop, Oura or Garmin.

Faster charging is the other agreed gain. Both Wareable and iPhone in Canada say 15 minutes on the charger gives up to 12 hours of use, up from 8 hours on earlier models.

Where they disagree

Battery life gives three different stories. Apple rates the watch at up to 24 hours, or 38 hours in Low Power Mode. Wareable’s reviewer got 30 to 35 hours but could not manage two nights of sleep tracking without charging, and lists barely improved battery life as a con. Macworld’s two test runs lasted about 51 and 40 hours, averaging 45.5, against 47.5 for the Series 11. That is the only review that found the new watch slightly worse than the old one. Macworld also found charging inconsistent: after half an hour one unit reached 58% and another reached 72%, against Apple’s 80% claim.

Reliability is the second split. Macworld’s reviewer reports a sharp edge where the screen meets the bezel, which he calls minor but unusual for Apple, and says a colleague saw the same. He also reports sluggish moments, missed activity detection and unexpected resets, three in one day. His summary:

“Not bad. But could do better.”

Neither Wareable nor iPhone in Canada reports such problems. That could mean Macworld got a rough unit, or that the issues are more common than two other reviews noticed. A single review cannot settle it.

The third difference is how much to trust launch-day features. iPhone in Canada says Live Rewind and Siri Recap are due in a later 2026 beta and need an iPhone 16 or newer, other than the 16e. It adds that hypertension notifications are not yet available in Canada. Macworld says to avoid buying primarily for features that have not shipped.

Who should buy it

All three reviews give the same upgrade advice with slightly different wording.

• Series 11 owners should skip it. iPhone in Canada says they can comfortably skip this generation, and Macworld says the gains are modest and found the Series 11 and SE 3 more reliable.
• Owners of older watches have a good reason. iPhone in Canada calls it worthwhile from a Series 8, Series 9 or older. Wareable says people who want the heart rate, Readiness and faster charging can reasonably upgrade, because those features do not reach the Series 11.
• First-time buyers get a safe choice. Wareable calls it an “outstanding all-rounder with ambitious new ideas” and says it remains the best choice for most iPhone owners. Macworld says it is a reasonable choice at its starting price if you want the latest design and sensors.

Prices vary by region. iPhone in Canada lists aluminium from $619 CAD and GPS plus cellular at $749, while Wareable gives titanium from $699 and ceramic from $899, both cellular-only.

What to watch: the Macworld hardware report. If more reviewers or owners find the sharp bezel edge or the random resets, it will matter more than any sensor result. Also watch whether the Readiness score gets deeper, since Wareable says rivals already go further.