Apple Watch Series 12

The Apple Watch Series 12 was introduced on 9 September 2026 and reached stores on 18 September. Apple's message is about sensing: a re-architected set of heart sensors and a new chip that it says give the most accurate heart rate sensing in a wearable. This page draws on Apple's product press release and its separate health announcement. Accuracy, battery and comparison statements are Apple's, and the company documents its own test conditions in the footnotes.

The Health Sensing System

The new sensor package combines optical and electrical heart sensors with the S11 chip, Apple's most powerful wearable chip. Apple says a study with more than 1,000 participants, drawn from different demographic groups, compared the new heart rate accuracy against leading wearables and found Apple Watch the most accurate. Larger, more power-efficient green LEDs let the watch measure heart rate every five seconds throughout the day, and a new watch face complication shows the live value at a glance. That constant stream is also used to make the Exercise and Move rings more precise.

Heart rate variability, which Apple calls a key indicator of stress and recovery, is measured up to 24 times more often, as frequently as every five minutes, and is shown in a new section of the Heart Rate app. Two variants are offered: recovery HRV, meant for daily signals of stress and recovery, and overall HRV, meant for the wider picture including cardiovascular health. Overnight vitals now compares recovery HRV with a personal baseline, and a new daytime vitals view lets users switch between night and day metrics, which Apple says can reveal shifts before they show overnight.

Readiness and the Health app

Readiness is new. It looks at recent activity, training load, vitals and sleep score and produces one score from 0 to 10 with a recommendation: Recover, Pace Yourself, Ready or Go For It. The score updates during the day and shows which factors drive it. Apple says the algorithm was developed with data from the Apple Heart and Movement Study together with its exercise scientists and physicians.

On the iPhone, a redesigned Health app arrives later in 2026, starting in U.S. English. It gets an Insights tab that summarises heart, sleep, readiness, fitness, vitals and cycle data through the day, and a Longevity tab with Health Age, an Apple Watch feature that shows how certain metrics track against the wearer's real age. The app also adds movement evaluations for flexibility, strength and balance using vision-based models on iPhone plus heart rate data from the watch. Apple also announced blood-test labs with more than 50 biomarkers for 119 dollars, bookable in the app at about 2,000 Quest Diagnostics locations in the U.S.

Audio Intelligence

The S11 chip and the built-in microphone enable four features. Sound Recognition alerts users who are deaf or hard of hearing to sounds such as sirens, alarms, doorbells or a crying baby, even when the iPhone is not nearby. Live Rewind shows the previous 15 seconds of a conversation as text after a double press of the Digital Crown. Siri Recap creates a short title and key points after a conversation in the new Siri app, and Shazam identifies music and shows it in the Smart Stack. Live Rewind and Siri Recap arrive later in 2026 as betas, need an Apple Intelligence iPhone 16 or later (excluding the 16e), start in English and are not initially available in the EU.

Apple stresses privacy. It says these features do not create or store audio recordings, and that raw audio is inaccessible to the operating system, apps, the user and Apple, because the S11 includes a hardware-isolated compartment called Secure Exclave that processes audio and immediately deletes it. Each feature is opt-in, Siri Recap can be switched off in Control Center, speakers are not identified, and Live Rewind plays a chime and shows a microphone indicator so people nearby know it is active. Summaries are end-to-end encrypted when synced through iCloud.

Battery, steps and design

Everyday battery life stays at up to 24 hours, while outdoor workout life rises to up to 10 hours, 25 percent more than the previous model. Fast charging gives up to 12 extra hours from 15 minutes on the charger, 50 percent more than before. The pedometer model was rebuilt with machine learning for better indoor walking and running distance and all-day step counts; Apple says it is the most accurate step tracking of any smartwatch, based on its own 1,000-step test, and a new Steps complication shows the count on the face.

The watch comes in 42 mm and 46 mm. Aluminum finishes are dark bronze, black, light gold and space gray; titanium comes in the new radiant gold and natural; and there is a ceramic version in pearl white and night blue, delivered with sand or navy Sport Bands that have a ceramic pin-and-tuck closure. Aluminum models now use Ceramic Shield 2, which Apple says is tougher than any smartwatch glass and 60 percent tougher than the Ion-X on earlier aluminum models. New bands include plaid Sport Loops printed with inkjet technology, a woven Modern Buckle with gold hardware and Nike colours, and Apple Watch Hermès adds a radiant gold titanium case and the Rocabar Club band.

watchOS 27 and Siri AI

With watchOS 27 the watch supports Siri AI, a new Siri app for continuing conversations and a Siri Modular watch face. Other additions are a dynamic app grid with five Siri-suggested apps, a one-handed tap gesture using index finger and thumb to open Smart Stack widgets, widget suggestions such as Parked Car, cycle tracking for perimenopause and menopause, and Workout Buddy without an iPhone nearby. watchOS 27 was due on 14 September for Series 9 or later, SE 3 and Ultra 2 or later.

Price and what is missing

The Series 12 starts at 399 dollars in the U.S. and could be pre-ordered from 9 September in Australia, Canada, France, Germany, India, Japan, the UAE, the UK, the U.S. and more than 50 other countries. New subscribers may get three months of Fitness+ and Apple Music. The press release does not give screen size in nits, water resistance, storage, or the weight of each case, and a redesigned Health app and several audio features arrive only later in the year.

Where it sits

The Series 12 replaces the Apple Watch Series 11. If you want a longer-lasting rugged model with the same sensors, look at the Apple Watch Ultra 4, and as a simpler alternative there is the Apple Watch SE 3. Android households can weigh it against the Pixel Watch 4 or the Galaxy Watch8, and the page Series 12 versus Series 11 shows the step from last year. See all smartwatches.