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WatchOS

Apple Watch operating system

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watchOS is the operating system of the Apple Watch, created and developed by Apple. It is based on iOS, the operating system used by the iPhone, and has many similar features. Its original version was released on April 24, 2015, along with the Apple Watch, the only device that runs watchOS. watchOS exposes an API called WatchKit for developer use.

01Interface overview

The home screen, rendered by and also known as "Carousel", consists of circular application icons that can be launched by touching the display, which allows users to access their favorite apps.

Prior to watchOS 3, "Glances" offered quick access to summaries of the most frequently used native and third-party applications. The Glances view was opened with a swipe-up gesture from the watch face screen. In watchOS 3, Glances were replaced with a redesigned Control Center that mirrors the functionality seen in iOS, providing a more unified experience across Apple devices. The Control Center is accessed with a swipe-up gesture from the watch face screen. Additionally, the friends menu, previously activated with the side button, was repurposed as a dedicated dock for apps, enhancing multitasking and app management.

Prior to watchOS 7, different actions and options appeared depending on whether the user taps or deep-presses, detected with the pressure-sensitive (Force Touch) Display. Force Touch was completely removed in watchOS 7, and all actions requiring the feature were moved to specific options in the Settings app or to long-press actions. With the launch of watchOS 7, Force Touch technology was phased out. This feature was replaced by additional options in the Settings app and extended press gestures to accommodate all necessary interactions, making it more consistent with other Apple devices that do not support Force Touch.

02Supported health metrics

Since its inception, watchOS has supported an increasing number and variety of health metrics for measurement and tracking. These include:

  • heart rate
  • maximal aerobic capacity, otherwise known as VO2 max. (added in watchOS 4, enhanced in watchOS 7)
  • electrocardiogram, otherwise known as EKG or ECG (added in watchOS 5.1.2)
  • blood oxygen saturation, otherwise known as SpO2 (added in watchOS 7)
  • menstrual cycle status (added in watchOS 6)
  • sleep duration & respiratory rate tracking (added in watchOS 7)
  • body temperature tracking (added in watchOS 9)
  • sleep apnea detection (added in watchOS 11)

03HealthKit

For several years, Apple has been developing its HealthKit product in an attempt to penetrate the lucrative healthcare and wellness industry, which CB Insights believe holds a huge growth opportunity for Apple. This was confirmed by Jony Ive, Apple's former chief designer, in an interview. He said that health was a crucial element in the Apple Watch since the day of its inception and that the developmental trajectory of the hardware and the watchOS were geared towards health-based capabilities. Ive pointed out that one of the primary apps that shipped with the first watchOS allowed users to track and communicate as well as encourage them to move, exercise, and stand. He said:

Many of us have our phones with us all the time, but they aren't connected to you. Imagine having something this powerful with you at all times, and what opportunities that might present to the user. The opportunity is phenomenal. Particularly when [you] don't understand just where we are today in terms of technology and capability, but where we are headed.

Applications have been developed for watchOS that not only keep users active but also diagnose illnesses. For example, the app called DeepHeart, a deep-learning network that can detect atrial fibrillation, hypertension, sleep apnea, and diabetes. It taps into the HealthKit platform to collect data, particularly those collected by the Apple Watch's heart sensor.

04Version history

Overview

Overview of watchOS versions
Version Initial release date Latest version Latest release date Device end-of-life
SE Series Ultra iPhone
watchOS 1 April 24, 2015 Unsupported: 1.0.1 May 19, 2015 , N/a , N/a
watchOS 2 September 21, 2015 Unsupported: 2.2.2 July 18, 2016
watchOS 3 September 13, 2016 Unsupported: 3.2.3 July 19, 2017 5, 5C
watchOS 4 September 19, 2017 Unsupported: 4.3.2 July 9, 2018 , N/a 1st , N/a , N/a
watchOS 5 September 17, 2018 Unsupported: 5.3.10 March 24, 2026 , N/a 5S, 6
watchOS 6 September 19, 2019 Unsupported: 6.3.1 February 2, 2026 , N/a 1, 2 , N/a , N/a
watchOS 7 September 16, 2020 Unsupported: 7.6.2 September 13, 2021 , N/a , N/a
watchOS 8 September 20, 2021 Unsupported: 8.8.2 March 24, 2026 , N/a 3 , N/a 6S, SE (1st), 7
watchOS 9 September 12, 2022 Unsupported: 9.6.4 February 2, 2026 , N/a 8, X
watchOS 10 September 18, 2023 Unsupported: 10.6.2 February 2, 2026 1st 4, 5 , N/a , N/a
watchOS 11 September 16, 2024 Supported: 11.6.2 February 5, 2026 , N/a XS, XR
watchOS 26 September 15, 2025 Supported: 26.6 July 27, 2026 2 6, 7, 8 1st , N/a
watchOS 27 September 14, 2026 Latest version: 27.0 September 14, 2026 TBA
Legend: Unsupported Supported Latest version Preview version Future version

watchOS 1

The first version of watchOS 1 was 1.0 and was based on iOS 8.2. The second version of watchOS 1 was 1.0.1 and was based on iOS 8.3.

watchOS 2

watchOS 3

watchOS 4

watchOS 5

watchOS 5 was first shown to the public at the 2018 San Jose WWDC developer conference held on June 4, 2018, by Apple. It had an instant watch-to-watch Walkie-Talkie mode. watchOS 5 was the first version of watchOS to bring 64-bit support.

watchOS 5 dropped support for the 1st-generation Apple Watch.

watchOS 6

Apple announced a new version of watchOS that would contain features such as the App Store, a calculator with tip tools, an audiobooks app, noise level monitoring, and Apple's Voice Memos app, at WWDC 2019 held on June 3, 2019. It also enables special games that can only be played on the Watch interface. With this release, Apple dropped support for iPhone 5s, 6, and 6 Plus. However, watchOS 6 has limited support on Apple Watch Series 1 and 2. watchOS 6.3 is the final release supported on the Apple Watch Series 1 and 2.

watchOS 7

Apple announced watchOS 7 at the 2020 Worldwide Developers Conference on June 22, 2020. With watchOS 7, Apple dropped support for Apple Watch Series 1 and 2. watchOS 7 has limited support on the Apple Watch Series 3.

watchOS 7 dropped support for the Apple Watch Series 1 and 2.

watchOS 8

Apple announced watchOS 8 at the 2021 Worldwide Developers Conference on June 7, 2021. Apple Watch models supporting watchOS 7 can also support watchOS 8. However, like watchOS 7, watchOS 8 has limited support on Apple Watch Series 3. It is also the last version of watchOS to be supported on Apple Watch models with 32-bit processors.

watchOS 9

Apple announced watchOS 9 at the 2022 Worldwide Developers Conference on June 6, 2022. With this release, Apple dropped support for the Apple Watch Series 3, which was the last Apple Watch model with a 32-bit processor, making watchOS 9 the first version of watchOS to run exclusively on Apple Watch models with 64-bit processors.

watchOS 10

Apple announced watchOS 10 at the 2023 Worldwide Developers Conference on June 5, 2023. With this release, Apple dropped support for iPhone 8, 8 Plus and X. All Apple Watch models supporting watchOS 9 also support watchOS 10.

watchOS 11

Apple announced watchOS 11 at the 2024 Worldwide Developers Conference on June 10, 2024. With this release, Apple drops support for the Apple Watch Series 4, Apple Watch Series 5 and Apple Watch SE (1st generation). This marks the first time 64-bit Apple Watch devices were dropped.

For legal reasons, blood oxygen monitoring was disabled on Series 9 and Ultra 2 Apple Watches sold in the United States after January 18, 2024. Apple Watch Series 10 was also incapable of blood oxygen monitoring at release. On August 14, 2025, Apple reintroduced blood oxygen monitoring for affected Series 9, Series 10, and Ultra 2 Apple Watches with watchOS 11.6.1.

watchOS 11 dropped support for the Apple Watch Series 4 and 5.

watchOS 26

Apple announced watchOS 26 at the 2025 Worldwide Developers Conference on June 9, 2025. watchOS 26 was released on September 15, 2025. All devices that supported watchOS 11 support watchOS 26.

Apple advanced the version number to 26 as part of a shift to a year-based versioning convention across its operating systems.

Supported: Overview of watchOS 26 versions
Version Build Release date Features
Unsupported: 26.0 23R352 September 15, 2025 Initial release on Apple Watch Series 11, Apple Watch SE (3rd generation), and Apple Watch Ultra 3

Drops support for iPhone XS, XS Max, and XR

  • New Watch faces: Exactograph, Flow, Waypoint, Hermès Faubourg Party, alongside enhancements to Photos face and a redesigned watch face gallery.
  • New unified Liquid Glass design language, which is used across Apple platforms
  • Hypertension Notifications for (Series 9, Ultra 2 or later)
  • Sleep Score
  • Workout Buddy (requires Apple Intelligence-capable iPhone)
  • Improved prediction algorithm for Smart Stack
  • Configurable widgets in Smart Stack
  • Live Translation for Messages (Series 9. Ultra 2 or later with Apple Intelligence-capable iPhone)
  • Smart Actions and more precise Smart Replies in Messages
  • Redesigned Workout app with intelligent media controls, now allowing Apple Music to select the best workout playlist
  • New Notes app
  • Wrist Flick gesture (Series 9, Ultra 2 or later)
  • Several watch faces and applications like Stopwatch and Timer get 1 Hz support that shows seconds ticking in always-on mode (Series 10 or later)
  • Automatic adjustment of volume of notifications, calls, timers, alarms, and Siri based on the environment
  • Hold Assist and Call Screening when iPhone is nearby

Security notes

Unsupported: 26.0.1 23R8352 September 18, 2025 Ultra 3 only
  • Enables Messages and Find My via satellite in Mexico

No security notes

Unsupported: 26.0.2 23R362 September 29, 2025
  • Bug fixes

No security notes

Unsupported: 26.1 23S37 November 3, 2025 Security notes
Unsupported: 26.2 23S303 December 12, 2025
  • Sleep Score notification controls and classification refinements
  • Enhanced Safety Alerts in the United States
  • Fixes bug in Music app where songs do not advance

Security notes

Unsupported: 26.2.1 23S314 January 26, 2026

No security notes

Unsupported: 26.3 23S620 February 11, 2026 Security notes
Unsupported: 26.4 23T240 March 24, 2026
  • Adds support for AirPods Max 2
  • Workout type icon in Workout app
  • New emoji based on Unicode 17.0

Security notes

Unsupported: 26.5 23T570 May 11, 2026 Security notes
Supported: 26.6 23U67 July 27, 2026 Security notes
Legend: Unsupported Supported Latest version Preview version Future version

watchOS 27

Apple announced watchOS 27 at the 2026 Worldwide Developers Conference on June 8, 2026. Apple dropped support for Apple Watch Series 6, Series 7, Series 8, Ultra (1st generation), and SE 2. watchOS 27 was released on September 14, 2026.

Latest version: Overview of watchOS 27 versions
Version Build Release date Features
Latest version: 27.0 24R364 September 14, 2026 Drops support for the Apple Watch Series 6, Apple Watch Series 7, Apple Watch Series 8, Apple Watch Ultra (1st generation), and Apple Watch SE 2.
  • Siri AI app
  • Dynamic app grid
  • Find My now unifies people, items and devices tracking into one map
  • Index-and-thumb widget control
  • Workout Buddy (requires Apple Intelligence) adds Spanish
  • Call Context surfaces relevant app data during ongoing phone calls
  • Cycle Tracking adds native perimenopause and menopause symptom logging
  • Wallet passes syncs custom user barcodes and QR codes from your iPhone
Legend: Unsupported Supported Latest version Preview version Future version

05Hardware support

Supported watchOS versions on the Apple Watch
Model watchOS
1 2 3 4 5 6 7 8 9 10 11 26 27
1st
Series 1 , N/a , N/a
Series 2 , N/a , N/a
Series 3 , N/a , N/a , N/a
Series 4 , N/a , N/a , N/a , N/a
Series 5 , N/a , N/a , N/a , N/a , N/a
SE (1st) , N/a , N/a , N/a , N/a , N/a , N/a
Series 6 , N/a , N/a , N/a , N/a , N/a , N/a
Series 7 , N/a , N/a , N/a , N/a , N/a , N/a , N/a
Series 8 , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a
Ultra (1st) , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a
SE (2nd) , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a
Series 9 , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a
Ultra 2 , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a
Series 10 , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a
SE 3 , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a
Series 11 , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a
Ultra 3 , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a
Series 12 , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a
Ultra 4 , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a , N/a
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Sources and credits

This article is adapted from the Wikipedia article WatchOS, written by its contributors and licensed under CC BY-SA 4.0. Fathomly has changed the layout, removed citation markers, navigation and maintenance notices, and adjusted punctuation. This adapted version is shared under the same license. For references, see the original article.

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