Smartwatches · 2026 · Apple

Apple Watch Series 12

A smartwatch combining an LTPO3 OLED display with heart, temperature and depth sensors. The case material also changes the cover glass: aluminium uses Ceramic Shield 2, while titanium and ceramic use sapphire.

42 / 46 mm · Case material options

Apple Watch Series 12 — Apple Watch Series 12 case options.
Apple Watch Series 12 case options.

Specifications

SpecificationValue
ProcessorS11; 64-bit dual-core; 4-core Neural Engine
Storage64 GB
DisplayAlways-On Retina LTPO3 OLED; 326 ppi; 2000 nits peak, 1 nit minimum; 46 mm: 416 × 496; 42 mm: 374 × 446

LTPO3 drops to 1 Hz in Always-On mode to save power.

Cover glassAluminium: Ceramic Shield 2; titanium/ceramic: sapphire
Case and material42 / 46 mm; aluminium, titanium or ceramic

Ceramic cases are slightly larger and thicker (9.85 mm); aluminium and titanium are 9.7 mm.

Rated battery lifeUp to 24 hours normal use; up to 38 hours Low Power Mode; up to 10 hours workout tracking

Apple's test profile; actual use varies.

Rated charging timeAbout 80% in 30 minutes; 15 minutes gives up to 12 hours of normal use

Apple measured these with a 20 W adapter that is not included; a USB-C fast-charging cable is in the box.

SensorsSecond-generation electrical and always-on optical heart sensors; blood oxygen; temperature; compass; always-on altimeter; high-g accelerometer; depth gauge to 6 m; water temperature
Health featuresECG; irregular rhythm and high/low heart rate notifications; hypertension and sleep apnoea notifications; sleep score; Vitals; Readiness

Some health features are limited by country and age; blood oxygen and temperature are not for medical use.

Weight46 mm aluminium GPS 39.5 g; titanium 44.9 g; 42 mm aluminium GPS 32.2 g; titanium 36.5 g
Durability50 m water resistance (ISO 22810:2010); IP6X dust

For swimming and snorkelling to 6 m, not scuba diving. Resistance can diminish over time.

ConnectivityWi-Fi 4 (2.4 and 5 GHz); Bluetooth 5.3; second-generation UWB; multi-constellation GPS; RedCap 5G on cellular models
CompatibilitywatchOS 27; iPhone 11 or later (including iPhone SE 2nd generation or later) running iOS 27

From the manufacturer

Apple highlights more frequent background heart rate measurements. Health notifications do not replace a medical diagnosis; app availability depends on country, age and the paired iPhone. Apple

Strengths and limitations

  • T3’s Matt Kollat measured about 46 hours from 100% to 20% in Low Power Mode on the 46 mm aluminium model, but roughly a day and a half in normal use, which he says lags rivals. Charging is quick: 20% to 35% in five minutes and 7% to 60% in about 18 minutes. Heart rate during runs and rides was within 1–2 bpm of a Garmin Fenix 9 Pro.

    The author’s 46 mm Dark Bronze test unit over several weeks; varies with usage.

    T3 — Matt Kollat: Apple Watch Series 12 review

  • Kollat criticised health data being spread across several apps and gesture controls remaining limited. He found that removing the Sleep Focus on the iPhone stopped the watch entering its sleep state, and that turning off haptics to silence WhatsApp also disabled alarm and workout haptics.

    watchOS version at the time of review; may change with software updates.

    T3 — Matt Kollat: Apple Watch Series 12 review

  • Because of the new health sensing system, Apple says hypertension notifications may be unavailable on Series 12 in 33 countries and regions, including Canada, Australia, India, Brazil and Japan, until additional regulatory clearances are complete. The US, UK and EU are not on that list.

    Status as of September 2026; clearances may change by country. Apple’s feature availability page is authoritative.

    MacRumors: Upgrading to Apple Watch Series 12 could cost you hypertension notifications

Owner experiences and issues

  • Buyers of the 46 mm GPS aluminium model at Best Buy mostly praise battery life; CHRISTIANT and another buyer report close to two days. One buyer upgrading from a Series 8 noted that blood oxygen results no longer appear on the watch face and have to be checked on the iPhone.

    US model MJEK4LS/A; a small number of verified, incentivised reviews, ownership one to three weeks. Blood oxygen display can vary by country.

    Best Buy: Apple Watch Series 12 GPS 46mm aluminum (MJEK4LS/A) customer reviews

Tags

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Sources

  1. Apple: Series 12 specifications
  2. Apple: Series 12 announcement
  3. T3 — Matt Kollat: Apple Watch Series 12 review
  4. MacRumors: Upgrading to Apple Watch Series 12 could cost you hypertension notifications
  5. Best Buy: Apple Watch Series 12 GPS 46mm aluminum (MJEK4LS/A) customer reviews