If you already own an Apple Watch Series 9, Series 10, Series 11, SE 3, Ultra 2 or Ultra 3, watchOS 27 costs you nothing on Monday, September 14, and it brings 14 confirmed changes to a watch you have owned for up to three years. None of them require the new Series 12 or Ultra 4.
That matters this week because Apple is selling new hardware four days later. Separating the free software from the $399 and $799 purchases is the only way to tell which of last week’s announcements you actually have to pay for.
| Key fact | Detail |
|---|---|
| Cost | Free, Monday, September 14, 2026 |
| Watches covered here | SE 3, Series 9, Series 10, Series 11, Ultra 2, Ultra 3 |
| Requirement | An iPhone 11 or later, or iPhone SE (2nd generation) or later, on iOS 27 |
| Free features confirmed | 14, listed below |
| Not included | Audio Intelligence and the Health Sensing System readings, both tied to Series 12 and Ultra 4 |
Which Apple Watches this covers
Apple’s watchOS page lists eight compatible models. Six of them are watches already on wrists: Apple Watch SE 3, Series 9, Series 10, Series 11, Ultra 2 and Ultra 3. The other two, Series 12 and Ultra 4, arrive with watchOS 27 installed.
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Apple Watch Series 6, Series 7, Series 8, SE (2nd generation) and the original Ultra are not on the list.
The 14 features you get for nothing
- The Liquid Glass display design
- A dynamic app grid that suggests the apps you use most, with the Siri app featured
- A one-handed tap gesture, index finger to thumb, that selects Smart Stack widgets
- Smart Stack suggestions tied to context, such as birthdays, a parked car and transit cards
- A Siri Modular watch face
- Workout Buddy, now with pace, distance and duration insights
- Workout Buddy without a nearby iPhone, running over Wi-Fi or cellular
- Workout Buddy in Spanish as well as English
- Better distance accuracy on treadmill and indoor walk workouts
- Perimenopause and menopause notifications in Cycle Tracking, with educational material
- A streamlined Find My app that combines Devices, People and Items on one map
- Call Context, which pulls up reservation codes and confirmation numbers when you call a business
- Faster playback startup in Music, plus step counts syncing to the Health app
- Custom QR and barcode passes in Wallet, and Apple Watch For Your Kids setup without an iPhone
Siri AI is free too, with three conditions
Siri AI is part of watchOS 27 rather than a Series 12 feature, and Apple lists Apple Watch Series 9 and later, Ultra 2 and later and SE 3 as capable of it. The conditions sit elsewhere.
First, the watch has to be paired with an Apple Intelligence iPhone, which means an iPhone 15 Pro, iPhone 15 Pro Max or an iPhone 16 or later. Second, Siri AI is in beta and available in English to start, with French, Japanese, Korean, Portuguese and Spanish coming in October. Third, Apple says Siri AI will not be available initially in the EU on iOS, iPadOS or watchOS, and that it is not available to users under 13.
What the free update does not include
Two of the loudest announcements from last week’s event are hardware, not software. Audio Intelligence, which covers Sound Recognition, Music Recognition with Shazam, Live Rewind and Siri Recap, is documented by Apple as requiring an Apple Watch Series 12 or Apple Watch Ultra 4. So is the Health Sensing System that measures heart rate every five seconds and heart rate variability every five minutes.
| Announced feature | Free on an older watch? |
|---|---|
| Siri AI, app grid, tap gesture, Smart Stack, Workout Buddy | Yes, with an Apple Intelligence iPhone for Siri AI |
| Cycle Tracking perimenopause support, Find My, Call Context, Wallet passes | Yes |
| Sound Recognition, Shazam, Live Rewind, Siri Recap | No, Series 12 or Ultra 4 only |
| Heart rate every 5 seconds, HRV every 5 minutes, Recovery HRV | No, new sensors only |
| Redesigned Health app, Health Age, Longevity tab | On iPhone, later this year, starting in U.S. English |
The Readiness score is the one item Apple has left ambiguous. It was introduced alongside Series 12 and Ultra 4, but Apple’s health press release lists device requirements of Apple Watch Series 9 or later, Ultra 2 or later and SE 3. Apple has not published a per-feature breakdown, so treat Readiness on an older watch as unconfirmed.
What Apple has not said
Apple has not stated a release time for Monday, has not published an About watchOS 27 Updates support document, and has not said which of the new health tools reach older watches. It has also not published a date for the redesigned Health app beyond later this year.
The update is due Monday, September 14. If you want the features that are not in it, Series 12 and Ultra 4 reach stores on Friday, September 18.
