watchOS

watchOS
watchOS
	A customized watch face on watchOS 6
Developer	Apple
Written in	C; C++; Objective-C; Swift; assembly language;
OS family	Unix-like, iOS based on Darwin
Working state	Current
Source model	Closed, with open-source components
Initial release	April 24, 2015
Latest release	26.6 (July 27, 2026) [±]
Marketing target	Smartwatch
Available in	45 languages
Update method	OTA (via iPhone 5 and later running iOS 8.2 and later)
Supported platforms	ARMv8-A (5.0–present); ARMv7-A (1.0–8.8.2);
Kernel type	Hybrid (XNU)
Default; user interface	Cocoa Touch (GUI)
License	Proprietary software except for open-source components
Official website	apple.com/os/watchos
Articles in the series
	iOS; iPadOS; macOS; visionOS; tvOS

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.