The Apple Watch Series 12 Sells a Five-Second Heart Sensor

Apple priced Apple Watch Series 12 from $399 and Ultra 4 from $799, with store availability on September 18. Both watches use a new S11 chip and take background heart rate every five seconds.

Siri AI still arrives on older models through watchOS 27 on September 14. The hardware you pay for is the denser heart sensor, a readiness score, and Audio Intelligence that older watches cannot run.

Five-Second Heart Rate, All Day Long

Apple’s pitch for Series 12 is a rebuilt Health Sensing System: new optical and electrical heart sensors, larger green LEDs, and photodiodes set in a ring. Staff at the launch described a 32-petal layout against the two-petal design on older models. The company says that array delivers the most accurate heart rate sensing in a wearable, based on a study of more than 1,000 people compared with other leading wearables.

Background heart rate now lands every five seconds all day, which Apple calls 60 times more frequent than Series 11. Heart rate variability is measured as often as every five minutes, 24 times more often than before, and the Heart Rate app now splits it in two. Recovery HRV is the daily stress and rest read. Overall HRV is the longer cardiovascular view.

WHAT THE NEW WATCHES ADD

Overnight vitals now include Recovery HRV set against a personal baseline, and a daytime vitals view lets you toggle the same metrics before they show up overnight. Readiness turns that stream into a single 0-10 score that updates after a hard workout or a swing in daytime vitals. Apple built the scoring with data from its Heart and Movement Study, working with its own exercise scientists and physicians.

Series 12 still claims up to 24 hours of everyday use and up to 38 hours in Low Power Mode. Outdoor workout life is now up to 10 hours, 25 percent more than the prior 8 hours. A 15-minute charge is rated for up to 12 hours, 50 percent more than the prior 8 hours from the same plug-in. The shop listing still puts 0-80 percent at about 30 minutes.

Audio Intelligence Stays Locked to the S11 Chip

Conversational Siri AI is a watchOS 27 feature. Audio Intelligence is not. Sound Recognition, automatic Shazam, Live Rewind, and Siri Recap need Series 12 or Ultra 4 because the S11 chip carries a Secure Exclave, a hardware-isolated buffer that processes microphone audio apart from the rest of the system.

Live Rewind and Siri Recap also need a recent iPhone: iPhone 16 and later, including iPhone 17, iPhone Air, iPhone 18 Pro, iPhone 18 Pro Max, and iPhone Duo. They arrive in beta later this year, in English first. They are off for users under 13, and a parent must turn them on for a Child Account under 18. Siri AI itself rolls out as a beta on September 14 in English, with French, Japanese, Korean, Portuguese, and Spanish due in October, and Apple says it will not be available in the EU at first on iOS, iPadOS, or watchOS.

FOUR AUDIO INTELLIGENCE FEATURES

• Sound Recognition: Alerts for sirens, alarms, doorbells, or a baby crying, even when the iPhone is not nearby.
• Music Recognition: Shazam writes the song title and artist into the Smart Stack without a tap.
• Live Rewind: A double press of the Digital Crown shows the last 15 seconds as text; a chime plays even on silent, with a full-display mic indicator.
• Siri Recap: Opt-in summaries of conversations, with a time or location schedule, auto-deleted after 7 days if you do not save them.

Apple’s privacy page is blunt about what the feature does not keep. Live Rewind snippets vanish about 30 seconds after the display dims unless you save them or tap Ask Siri. Recaps are high-level notes, not a transcript, and they skip speaker labels on purpose.

Audio Intelligence features don’t create audio recordings. No audio can be accessed by the operating system, apps, you, or even Apple. There is no recording to share, forward, or produce if requested by any party, because no recording exists.

Apple Support, About Audio Intelligence features on Apple Watch Series 12 and Apple Watch Ultra 4

Apple also says audio is not recorded or stored, that raw audio never leaves the Secure Exclave in usable form, and that saved recaps sync end-to-end encrypted through iCloud. The catch for buyers is simpler than the silicon story: a Series 11 on watchOS 27 still gets the new Siri. It does not get the microphone features that need S11.

What Older Apple Watches Get on September 14

watchOS 27 ships Monday, September 14, four days before the new watches reach stores. Apple’s list is Apple Watch SE 3, Series 9 and later, and Ultra 2 and later, paired with iPhone 11 or later or iPhone SE (2nd generation or later) running iOS 27. Series 8 and earlier, the first Ultra, and older SE models are out.

WATCHOS 27 ON COMPATIBLE OLDER MODELS

• Siri AI: A dedicated Siri app and a Siri Modular watch face, in English at first, when the watch is paired with a supported iPhone.
• Dynamic app grid: Five Siri-suggested apps drawn from most-used and recently used titles, plus a path to the full grid.
• One-handed taps: Index finger and thumb tap to open a Smart Stack widget; double tap to scroll; wrist flick to return to the face, silence timers, and dismiss alerts.
• Workout Buddy: Runs without the iPhone nearby, uses more fitness data, and adds Spanish beside English.
• Walkie-Talkie: Removed from the app list and Control Center, with no reinstall path.

That split is why a Series 9, 10, or 11 owner can wait. They get the assistant, the grid, and the new gestures on September 14. They do not get five-second heart rate, the 0-10 readiness score, or Recap. Health Age, which lands later this year in a redesigned Health app, can draw on older Watch data, but the denser HRV feed that Apple is selling sits on the new sensor.

$899 Ceramic Comes Back After Six Years

Series 12 still looks like Series 11: 42 mm or 46 mm, 2,000-nit always-on display, 50 meters of water resistance. The new aluminum color is dark bronze, beside black, light gold, and space gray. Titanium adds radiant gold next to natural. Aluminum faces now use Ceramic Shield 2, which Apple says is 60 percent tougher than the Ion-X glass on prior aluminum models.

The case that people argued about before the event is ceramic, in pearl white and night blue. Launch listings put 42 mm ceramic GPS plus cellular at $899 and 46 mm at $949, a $500 jump over the $399 aluminum GPS start. Titanium GPS plus cellular is listed from $699 and $749. Cellular aluminum is $499 and $549. GPS aluminum is $399 for 42 mm and $449 for 46 mm. Ultra 4 holds at $799 for the 49 mm titanium watch.

U.S. LAUNCH LISTINGS

Ceramic is heavier and a touch taller. Apple’s spec sheet lists the 46 mm pearl white ceramic at 51.3 grams and 47 mm in height, against 39.5 grams and 46 mm for aluminum GPS. Night blue ceramic is 52.9 grams. The last time Apple sold this material was Series 5; it disappeared when Series 6 arrived in 2020, a six-year gap.

Collectors already knew the look from the white ceramic Edition from 2016, when Apple used ceramic to replace the gold Edition and priced the 38 mm watch at $1,249. The $1,299 white ceramic Series 2 sat next to it. Series 12 ceramic undercuts that old Edition tag by $350 and sits in the regular lineup, not a separate Edition brand. That is the version of “luxury” Apple is willing to sell this time.

Apple Watch Series 12 is the most advanced health and fitness companion we’ve ever created. With our new Health Sensing System and S11 chip, Apple Watch Series 12 gives you meaningful insights, like readiness, so you can better understand how to take on your day and care for your health, plus intelligence features that make everyday life easier.

Kaiann Drance, vice president of Worldwide Apple Watch Product Marketing, Apple newsroom

Apple also says Series 12 is made with 40 percent recycled material overall, including 100 percent recycled aluminum in the aluminum case and 100 percent recycled titanium in the 3D-printed titanium case. Preorders opened September 9 in the U.S. and more than 50 other countries. Apple Upgrade in the U.S. lists 24-month terms from $11.99 a month.

The Ultra 4 Battery Finally Clears Two Days

Ultra 4 keeps the 49 mm Grade 5 titanium body, 3,000-nit display, 100-meter rating, dual-frequency GPS, depth gauge, water temperature sensor, siren, and satellite emergency tools. It shares the S11 chip, Health Sensing System, readiness score, and Audio Intelligence with Series 12. The gap you can feel without a lab is power.

ULTRA 4 BATTERY CLAIMS

• Everyday use: Up to 50 hours, 8 hours more than the 42-hour Ultra 3 rating.
• Low Power Mode: Up to 84 hours, 12 hours more than Ultra 3.
• 15-minute charge: Up to 18 hours of extra use.
• Long workouts: Up to 25 hours in Extended Workout with full GPS and heart rate, 25 percent more than before, and up to 45 hours in Max Extended Workout with GPS once a second, which Apple says is typically enough for a 100-mile race.

Natural and black titanium return. Hermès remains a separate Ultra 4 configuration. If you already own Ultra 3, the sensor and the extra day of battery are the upgrade case. Siri AI is not, because Ultra 2 and Ultra 3 pick that up on September 14.

Quest Diagnostics Enters the Health App for $119

The redesigned Health app is an iPhone update due later this year, starting in U.S. English. An Insights tab will refresh through the day across heart, sleep, readiness, fitness, vitals, and cycle data. A Longevity tab rolls those streams into heart, sleep, mental wellbeing, movement, metabolic health, hearing, and nutrition. Health Age sits in that tab and compares Watch metrics with chronological age.

Sumbul Desai, M.D., Apple’s vice president of Health and Fitness, said the company is combining the new sensing with Apple Intelligence “to translate complex biometric data into clear guidance for users.” The algorithm can use VO2 max, resting heart rate, sleep, and HRV from the Watch, and it can take lab values such as A1c and LDL when you add them.

WHAT FEEDS HEALTH AGE

• Watch metrics: VO2 max, resting heart rate, sleep, and HRV, with denser HRV on Series 12 and Ultra 4.
• Optional bloodwork: A1c, LDL, and a panel of over 50 biomarkers.
• Other inputs: iPhone, AirPods, clinical records, and third-party apps and devices.

That panel is a product. Users will be able to schedule and buy labs with over 50 biomarkers for $119 through the Health app at about 2,000 Quest Diagnostics sites in the U.S. Movement evaluations are a separate on-device path: flexibility, strength, balance, movement mechanics, and VO2 max using the iPhone camera and Apple Watch, with no video recorded or stored.

Perimenopause Alerts Start at Age 40

Cycle Tracking in iOS 27 adds perimenopause and menopause logging, symptom tracking, and notices when cycle patterns look off. Users age 40 and over can get a notice if a logged-cycle change looks like perimenopause, so they can raise it with a doctor. Bleeding after menopause triggers a prompt to speak with a clinician. Workout tracking also gains a Functional Strength mode that logs sets, repetitions, weights, and equipment, and Workout Buddy can now run on the Watch alone.

None of those Health app pieces require you to stand in line on September 18. The $119 Quest checkout and Health Age land later this year. The Watch you buy this month is the sensor that will feed them at a higher rate.

Apple Drops Walkie-Talkie in watchOS 27

Walkie-Talkie arrived with watchOS 5 in 2018 as push-to-talk between two Apple Watches over Wi-Fi or cellular. Apple had to shut it off shortly after launch because of an eavesdropping bug, then brought it back and left it alone for eight major releases. watchOS 27 removes the app and its Control Center tile. Apple has not said why.

The same software drop that deletes that two-way voice toy is the one that puts Recap on new hardware, with a chime so the room can hear the crown click. Recap is opt-in, scheduled, and, Apple says, empty of audio files. It is also absent at launch, stuck in a later beta, and tied to iPhone 16 and newer. The part you can actually wear home on September 18 is still the five-second heart sensor, the 0-10 readiness score, and, if you spend $899, a ceramic case Apple has not sold since 2020.

Disclaimer: This article is news reporting on Apple’s September 9, 2026 Watch announcements and is for information only. It is not medical advice, a diagnosis, or a recommendation to buy a wearable, a readiness score, a Health Age reading, or a lab panel. Speak with a licensed physician or other qualified clinician before you act on heart-rate, HRV, cycle, or bloodwork information, and confirm prices and feature lists with Apple or Quest Diagnostics, because software dates, regional limits, and lab availability can change after the announcement.