watchOS is the

operating system An operating system (OS) is system software that manages computer hardware and software resources, and provides common daemon (computing), services for computer programs. Time-sharing operating systems scheduler (computing), schedule tasks for ...

of the

Apple Watch The Apple Watch is a brand of smartwatch products developed and marketed by Apple Inc., Apple. It incorporates activity tracker, fitness tracking, Health (Apple), health-oriented capabilities, and wireless telecommunication, and integrates wit ...

, developed by

Apple An apple is a round, edible fruit produced by an apple tree (''Malus'' spp.). Fruit trees of the orchard or domestic apple (''Malus domestica''), the most widely grown in the genus, are agriculture, cultivated worldwide. The tree originated ...

. It is based on

iOS Ios, Io or Nio (, ; ; locally Nios, Νιός) is a Greek island in the Cyclades group in the Aegean Sea. Ios is a hilly island with cliffs down to the sea on most sides. It is situated halfway between Naxos and Santorini. It is about long an ...

, the operating system used by the

iPhone The iPhone is a line of smartphones developed and marketed by Apple that run iOS, the company's own mobile operating system. The first-generation iPhone was announced by then–Apple CEO and co-founder Steve Jobs on January 9, 2007, at ...

, and has many similar features. It was released on April 24, 2015, along with the Apple Watch, the only device that runs watchOS. watchOS exposes an

API An application programming interface (API) is a connection between computers or between computer programs. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how to build ...

called

WatchKit WatchKit is a framework provided by Apple to develop applications for the Apple Watch. The WatchKit framework is designed for the Swift programming language and also the Objective-C programming language and must be compiled in Xcode, similar to ...

for developer use. The second version, watchOS 2, included support for native third-party apps and other improvements, and was released on September 21, 2015. The third version, watchOS 3, was released on September 13, 2016, to emphasize better performance and include new watch faces and stock apps. The fourth version, watchOS 4, was released on September 19, 2017. The fifth version, watchOS 5, was released on September 17, 2018, to add more third-party support and new workouts, along with the " Walkie-Talkie" feature. The sixth version, watchOS 6, was released on September 19, 2019. The seventh version, watchOS 7, was released on September 16, 2020, to support handwashing and sleep tracking. The eighth version, watchOS 8, was released on September 20, 2021, with updates in health monitoring, visuals, and apps. The ninth version, watchOS 9, was released on September 12, 2022. The tenth version, watchOS 10, was released on September 18, 2023. The 11th and the latest version, watchOS 11, was released on September 16, 2024. The 12th version, watchOS 26, was announced on June 9, 2025.

Interface overview

The home screen, rendered by and also known as "Carousel", consists of circular application icons that can be zoomed in and out with the Digital Crown and launched by touching the display, allowing 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, which an Apple Watch detects with its pressure-sensitive (

Force Touch Force Touch is a haptic pressure-sensing technology developed by Apple Inc. that enables trackpads and touchscreens to sense the amount of force being applied to their surfaces. Software that uses Force Touch can distinguish between various ...

) 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. This change streamlined the interaction model, making it more consistent with other Apple devices that do not support Force Touch. As of watchOS 10, the interface has been further refined to enhance user accessibility and interaction. New customization features allow users to personalize their Carousel with greater ease, and improvements in app responsiveness and animation enrich the overall user experience. These updates demonstrate Apple's ongoing commitment to enhancing usability while maintaining the sleek, minimalist design that users appreciate.

Supported 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 V̇O2 max (also maximal oxygen consumption, maximal oxygen uptake or maximal aerobic capacity) is the maximum rate of respiration (physiology), oxygen consumption attainable during physical exertion. The name is derived from three abbreviations ...

(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, unavailable on Apple Watch Series 9 and Ultra 2 units sold after January 15, 2024 for legal reasons) *

menstrual cycle The menstrual cycle is a series of natural changes in hormone production and the structures of the uterus and ovaries of the female reproductive system that makes pregnancy possible. The ovarian cycle controls the production and release of eg ...

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)

HealthKit

For several years, Apple has been developing its HealthKit product in an attempt to penetrate the lucrative

healthcare Health care, or healthcare, is the improvement or maintenance of health via the preventive healthcare, prevention, diagnosis, therapy, treatment, wikt:amelioration, amelioration or cure of disease, illness, injury, and other disability, physic ...

and wellness industry, which

CB Insights CB Insights is a private company with a business analytics platform and global database that provides market intelligence on private companies and investor activities. The platform is targeted at private equity, venture capital, investment bank ...

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 oudon'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 Atrial fibrillation (AF, AFib or A-fib) is an Heart arrhythmia, abnormal heart rhythm (arrhythmia) characterized by fibrillation, rapid and irregular beating of the Atrium (heart), atrial chambers of the heart. It often begins as short periods ...

hypertension Hypertension, also known as high blood pressure, is a Chronic condition, long-term Disease, medical condition in which the blood pressure in the artery, arteries is persistently elevated. High blood pressure usually does not cause symptoms i ...

, sleep apnea, and

diabetes Diabetes mellitus, commonly known as diabetes, is a group of common endocrine diseases characterized by sustained high blood sugar levels. Diabetes is due to either the pancreas not producing enough of the hormone insulin, or the cells of th ...

. It taps into the HealthKit platform to collect data, particularly those collected by the Apple Watch's heart sensor.

Version history

Overview

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. With this release, Apple dropped support for the first generation Apple Watch. watchOS 5 was the first version of watchOS to bring 64-bit support.

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 3 June 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 The Worldwide Developers Conference (WWDC) is an information technology conference held annually by Apple Inc. The conference is currently held at Apple Park in California. The event is used to showcase new software and technologies in the macO ...

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 8

Apple announced watchOS 8 at the 2021

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

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

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

on June 10, 2024. With this release, Apple drops support for the

Apple Watch Series 4 The Apple Watch is a brand of smartwatch products developed and marketed by Apple. It incorporates fitness tracking, health-oriented capabilities, and wireless telecommunication, and integrates with watchOS and other Apple products and serv ...

and Apple Watch Series 5. This marks the first time 64-bit Apple Watch devices were dropped.

watchOS 26

Hardware support

References

External links

* – official site
Apple security content
– for details about watchOS security updates
About watchOS 9 Updates
– Apple's official watchOS 9 release notes {{Apple Inc. IOS Apple Inc. operating systems 2015 software Apple Watch Smartwatches