What Is WatchOS?

Everything you need to know about Apple Watch software

Apple Watch on a wrist, showing the home screen app grid

Getty Images

watchOS is the software that makes your Apple Watch work. Much like macOS runs your MacBook, tvOS runs your Apple TV, and iOS runs your iPad and iPhone, watchOS, based on iOS, was first released along with the original Apple Watch in April of 2015.

The interface was a new one for Apple, with a home screen containing little round icons for all the apps the Apple Watch can run and a new Digital Crown button that rotates and can be pushed. The watchOS software allows the Digital Crown, which emulates a traditional watch crown, to scroll through lists of items and zoom in and out on the home screen. 

Initially, a companion device for Apple’s popular iPhone (many apps needed to be run in conjunction with iPhone apps via Bluetooth), the Apple Watch and its corresponding upgrades to watchOS, has become more and more of a standalone device, with the latest Series 4 Apple Watch including GPS and an optional cellular capability.

watchOS 6

Cycle Tracking app on an Apple Watch
 Apple Inc

Release date: September 19, 2019

Latest Version: 6.0.1, September 19, 2019

The sixth and latest iteration of watchOS brought with it a few good changes, like a dedicated watchOS App Store, new apps like Calculator, an Activity trends feature, and health-focused features like a menstrual cycle tracker and a hearing health app.

Apple’s watchOS 6 also brings new watch faces, an improved Siri that can tell you what song is playing nearby, automatic audiobook syncing, along with a redesigned Reminders app and a new Voice Memo app. Plus, you can finally add Animoji and Memoji stickers to your messages right from your wrist.

watchOS 5

Apple Watch with Pride rainbow band and watch face

Released: September 17, 2018
Latest version: 5.2.1, May 13, 2019
Beta version: 5.3 beta 3, June 11, 2019

watchOS 5 arrived with the latest iteration of Apple Watch hardware, Series 4. It brought with it a slew of new features and additions to the OS, including more fitness activities, apps, Siri abilities, and notification improvements. 

Apple’s Workout app got a new Compete with Friends system, auto-detection for workouts, and added Yoga and Hiking to the list of available tracking. Pace alerts and cadence tracking also showed up. A new Podcasts app arrived for watchOS, letting you stream your favorites via LTE or sync from your iPhone (for GPS-only devices). Walkie-Talkie also made its debut, letting you tap and hold an on-screen button to chat via voice just like a real walkie-talkie (the feature uses FaceTime Audio to do so). The Siri watch face now allows third-party apps support, and you can raise your wrist to activate Siri. Apple’s digital assistant also now integrates with Siri shortcuts, allowing for more complex responses to your commands.

Notifications are now grouped by app, and watchOS 5 gives you even more actions to handle them on your wrist. You can view webpages in iMessages and schedule Do Not Disturb events to happen when you leave a location or for a specific time period. If you’re a student, watchOS also offers support for contactless student ID cards, letting you access your dorm, the gym, and the library while also letting you pay for stuff on campus like laundry, coffee, or lunch. 

Key New Features:

  • Compete with Friends
  • Workout auto-detect, Yoga & Hiking added
  • Podcast apps
  • 3rd Party support for Siri watch face
  • New notification features
  • Student ID cards

watchOS 4

Apple Watch with green Sport band on a table
 William Hook / Flickr / CC By 2.0

Released: September 19, 2017
Final Version: 4.3.2 — July 9, 2018

This new iteration was the end of the road for the first-generation Apple Watch, with 4.3.2 being the final watchOS supported for that original device. There were also several changes to the OS as well, including a new List option for the home screen, which lets you see all your apps in a list interface, along with a new Favorites option for the Dock, so that you could choose what shows up when you press the Apple Watch side button. Previously, the Dock only showed your most recent apps. Even more new watch faces arrived with this version, including a kaleidoscope face, one with Toy Story characters on it, and a dedicated watch face for Siri. 

New activity reminders made their debut in watchOS4, too, with heart rate alerts also launching alongside. Apple Music got a boost, too, with an easier way to sync music from your iPhone and a promise of streaming. Another, perhaps less exciting yet still useful, feature was the added flashlight ability, which sets a bright-colored overlay on your watch face to help you see in the dark. 

Key New Features:

  • Home screen list option
  • Favorites for the Dock
  • New Siri watch face (with others)
  • Better music sync options
  • Heart rate alerts

watchOS 3

Hand holding a Nike Apple Watch with Night Sky 4 on the screen
Maurizio Pesce / Flickr / CC By 2.0

Released: September 13, 2016

A year after the previous version, watchOS 3.0 was released, bringing with it improved performance, new Watch faces, and more first-party stock apps. watchOS 3 was hailed as a fairly significant update, changing some of the interface elements like the function of the side button (it now opened a dock instead of a friends list). Control Center made its Apple Watch debut, too, activated with a swipe up on the screen. 

New watch faces were introduced with watchOS 3, along with more fitness-focused complications (the little bits of information on a watch face). Apple also made it easier for app developers to add complications for their third-party apps. A new first-party Breathe app made its initial appearance, and the Emergency SOS feature (that can notify chosen contacts and call 911) appeared. watchOS 3 brought new first-party apps, too, like Reminders, Home, Find My Friends, and a heart rate system. You could also now write messages, one letter at a time, with the Scribble feature. 

Key New Features:

  • Control center
  • Dock on side button press
  • Fitness-focused complications
  • Breathe app
  • New watch faces
  • First party app additions
  • Scribble text recognition

watchOS 2

Apple Watch with setup graphic on its screen
Charanjit Chana / Flickr / CC By 2.0

Released: September 21, 2015

The second iteration of watchOS (2.0), included support for native third-party apps that could run on the Apple Watch without having to “phone home” to an iPhone. For example, you could finally use Facebook Messenger to text and send audio files and share your location right from Apple Watch. GoPro users could now use their Apple Watch as a viewfinder for the popular action cameras, and iTranslate allowed for on-the-fly translation directly from your wrist. Native apps also ran faster than companion apps, since they didn’t need to send data to an external iPhone just to run.

watchOS 2.0 brought new capabilities to the Apple Watch, as well, like a Time Travel feature that lets users rotate the Digital Crown to view up to 72 hours forward and back in “time” for apps like Weather and News headlines. The new OS added new watch faces, display time-out options, easier email reply functions, and Music app improvements as well. Popular nightstand mode was also introduced here, letting Apple Watch users set their device on its side to show a minimalist time and alarm setting, complete with the Digital Crown acting as a snooze button. 

Key New Features:

  • Native third-party apps
  • Time travel
  • New watch faces
  • Display time-out options
  • Nightstand mode

watchOS 1

A display of Apple Watches in an Apple Store
Open Grid Scheduler / Grid Engine

Released: April 24, 2015

Initially announced alongside the first Apple Watch, watchOS 1 included the home screen, companion apps, and a Glances view, which let you see the data from apps you specify. Glances was like a little set of app widgets that you could swipe up from the bottom of your Apple Watch to access.

The side button opened up the Friends menu, which allowed users to see people they had specified as Apple Watch friends. You’d tap the button and then be able to send digital heartbeats, drawings, and heartbeats to those contacts. 

Siri was available in watchOS from day one, as was Force Touch, which continues to exist on the latest models. You could press and hold the Digital Crown to invoke Siri, or (optionally) call out “Hey Siri” to activate Apple’s digital assistant. watchOS 1 allowed you to do a lot on the original Apple Watch, like turning on Airplane mode, checking your calendar, and starting a workout.

Other first-party apps like Activity, which tracks your movement, workouts, and periods of standing throughout the day with a clever little circular “rings” interface, were available in watchOS 1.0, as well. You could also make phone calls and use Apple Pay with this original iteration, as well, though you needed your iPhone nearby for the calls.

Key New Features:

  • Glances view
  • Friends menu
  • Activity app
  • Force Touch