WatchOS
Apple Watch operating system

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
| 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
|
| Unsupported: 26.0.1 | 23R8352 | September 18, 2025 | Ultra 3 only
No security notes |
| Unsupported: 26.0.2 | 23R362 | September 29, 2025 |
No security notes |
| Unsupported: 26.1 | 23S37 | November 3, 2025 | Security notes |
| Unsupported: 26.2 | 23S303 | December 12, 2025 |
|
| 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 |
|
| 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.
|
| Legend: Unsupported Supported Latest version Preview version Future version | |||
05Hardware support
| 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 | |
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.
Images, from Wikimedia Commons:
- WatchOS 6 screenshot.jpg by Apple Inc., Fair use
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