Apple Watch Series 12 review: a more accurate heart sensor and better battery life, but still not your doctor

The Apple Watch Series 12 puts its weight mainly on health sensors. The new heart sensor measures heart rate every 5 seconds throughout the day (previously periodic), and HRV sampling is 24x more frequent, alongside a new Readiness Score from 0–10 that synthesizes activity, training load, vital signs, and sleep, offering guidance on whether to rest or push hard.

On battery, general use stays at 24 hours, but outdoor workout tracking rises to 10 hours (a 25% improvement), and a 15-minute fast charge adds 12 more hours of use (a 50% improvement). The device comes in 2 sizes, 42 and 46mm, with 3 material options: aluminum with Ceramic Shield 2 (60% tougher), titanium, and ceramic, with an external design barely different from the Series 11.

Audio Intelligence voice features like Live Rewind and Siri Recap remain in beta, launching late 2026, English-only, restricted in Europe, and requiring an iPhone 16 or later with Apple Intelligence support. Thailand pricing starts at 14,900–16,900 baht for aluminum GPS, 18,900–20,900 baht for aluminum GPS+Cellular, 25,900–27,900 baht for titanium, and 33,700–35,700 baht for ceramic. Pre-orders are open now, with sales starting September 18. Analysis suggests this suits those wanting detailed heart-health data or upgrading from a Series 8 or older; Series 10/11 owners can likely skip this generation.