The Apple Watch Series 12 introduces a more substantial set of changes than the Series 11, which was one of the smallest refreshes in the device's history. Since Apple Watch generation-over-generation enhancements are relatively small, it is important to consider when an upgrade is justified and whether an older model could suffice for your needs. The Series 12 features the S11 chip based on A20 Pro, 4GB of RAM, a new Health Sensing System, and second-generation electrical heart sensor.
It includes fourth-generation always-on optical heart sensor with background heart rate measurements every five seconds and heart rate variability measured up to 24x more often. Additional health features are Recovery HRV metric, Readiness app, and daytime view in the Vitals app. Step tracking is more accurate with steps and real-time heart rate watch face complications.
Audio Intelligence adds Sound Recognition and automatic Shazam detection, along with Live Rewind and Siri Recap. The Ceramic Shield 2 front glass is 60% tougher than Series 11's Ion-X glass on aluminum models. Aluminum or titanium and zirconia back replaces metal and sapphire crystal back.
Outdoor workout tracking extends to up to 10 hours (25% longer than Series 11). Charging improvements include 15 minutes providing up to 12 hours of normal use (up from eight hours) and five minutes enabling up to 10 hours of sleep tracking (up from eight hours). Aluminum and titanium cases are 1mm wider and about two grams heavier, with slightly larger bezels and display area approximately 2% smaller despite unchanged resolutions.
Ceramic case option arrives in Pearl White and Night Blue. Dark Bronze, Light Gold, and Black aluminum finishes replace Silver, Rose Gold, and Jet Black; Space Gray remains available. Radiant Gold titanium replaces Gold and Slate; Natural titanium remains available.
The Series 11 offered 2x more scratch-resistant Ion-X glass (aluminum only), 5G connectivity (cellular models), 7–10% larger battery, and reintroduced Space Gray aluminum option. The Series 10 featured refined design with thinner casing, rounded edges, wider aspect ratio, and front glass extending further for higher screen-to-body ratio. It had 42mm and 46mm case sizes, larger displays, LTPO3 display for faster refresh rate enabling live ticking seconds hand, wide-angle OLED up to 40% brighter at angle, S10 chip (same CPU as S9 but more compact), water temperature sensor, Depth app and gauge to 6m, microphone with voice isolation, redesigned speaker with media playback, metal back with larger charging coil and integrated antenna, faster charging (0–80% in ~30 minutes), titanium casing replacing stainless steel in Silver, Gold, Slate, and Natural, and finish changes including discontinuation of Starlight, Midnight, Pink, and (PRODUCT)RED.
Source: MacRumors · Summarized by HeadlinesBriefing