Skip to content

Most visited

Recently visited

navigation

Wear OS preview downloads

You can run and test your app with the Wear OS by Google Preview in either of these ways:

  • Install Wear OS on a supported watch, or
  • Set up an emulator that is running the Wear OS Preview

If you want an environment for basic compatibility testing of your app, you can use your current APK and a supported watch or an emulator. As described below, you don't necessarily need to update your full development environment to do basic testing.

However, if you want to modify your app to target the upcoming version of Wear OS, or use Android P APIs, you need to update your development environment. See Wear OS preview setup.

Set up a watch

You can download a system image and manually flash it to a matching watch. Manually flashing a watch is useful if you need precise control over the test environment or need to reinstall frequently, such as for automated testing.

Warning: Installing a system image on a watch removes all data from the watch. You should back up your data first.

Preview system images

The preview includes system images for testing your app. If you have a Huawei Watch 2 Bluetooth or Huawei Watch 2 Classic Bluetooth watch, you can download the preview system image from the table below and flash it to the watch. For the China version of Wear OS, see Wear OS for China developer preview.

Caution: After you flash an image to a watch, follow the steps to set up a phone. To use a Wear preview image on a watch, you must have a recent version of the companion app on a paired phone.

After a watch is flashed with a Wear preview image, subsequent releases can automatically be delivered via OTA, and may result in an automatic deletion of all data on the watch.

To restore your watch to its original state during the preview, flash the watch with the appropriate retail system image, below.

Preview image for Huawei Watch 2 Bluetooth

Caution: Flashing your watch will require unlocking the bootloader which shall void the watch's warranty—proceed at your own risk.

Type of Huawei Watch 2 image Download/Checksums
Preview image for testing sawfish-PWH1.180318.006.tgz
MD5: 98a0571379241c2ff5a527cedc26b0cd
SHA-1: 40f1f2f4516c2269b467f1005cbf2c9312e12ead
Non-preview image (for after testing) sawfish-factory-OWDD.180215.018.tgz
MD5: 3a32221c7bfeae7bc89336724a05f7d3
SHA-1: 33065ba28e96a9457186ffefe6632731dcb5db8a

Flash a watch

The steps for flashing an image to a watch are similar to the steps provided for flashing to a phone. After you back up your watch data, use steps in this section to flash the image to your watch. For this release, you must use a Huawei Watch 2 Bluetooth or Huawei Watch 2 Classic Bluetooth.

Warning: Installing a system image on a watch removes all data from the watch. You should back up your data first.

Set up the watch to be flashed

On the watch, enable the Developer Options menu and ADB debugging as follows:

  1. Open the Settings menu on the watch.
  2. Scroll to Developer options item at the bottom of the menu. If you have not enabled the developer options, do so now:
    1. Tap System and then About.
    2. Tap the Build number 7 times.
    3. Return to the Settings menu and tap Developer options.
  3. Enable ADB debugging.

Confirm installation of the fastboot tool

Caution: To flash a watch using one of the system images, confirm that you have the fastboot tool in the platform-tools/ directory of the Android SDK. Be sure that you have the latest version of the SDK Platform and SDK Tools from the SDK Manager.

After you confirm that you have the fastboot tool, add the tool to your PATH environment variable so the tool can be found when you flash the watch.

Transfer the image to the watch

To download the preview image and flash it to the watch:

  1. Download and unzip the system image from the "Preview image for testing" row in the table above.
  2. Attach the watch charger to the watch and plug the USB cord (from the charger) into your computer.
  3. Use the following adb command to confirm that the watch is recognized. You may need to turn ADB debugging off and then on for the watch to be recognized: adb devices
  4. Use the following adb command to start the watch in fastboot mode: adb reboot bootloader
  5. If required, use the fastboot oem unlock command to unlock the watch's bootloader. This step erases all data on the watch.
  6. On the watch, select the option to unlock the bootloader. This is usually a short press on the physical button.
  7. On your computer, navigate to the directory where you unzipped the system image in Step 1. At the top level of that directory, execute the flash-all script:
    • On Linux or MacOS, type ./flash-all.sh

      Note: You may need to set the execute permission bits for the script: chmod 755 flash-all.sh

    • On Windows, type flash-all.bat

Set up the watch

After the flash-all script finishes, the watch reboots. Pair the watch with a phone (so you can begin testing the preview) by using the instructions to set up a phone. Additionally, before installing an app, perform the following steps on the watch to re-secure the watch's bootloader:

  1. Open the Settings menu by long-pressing the physical button.
  2. Scroll to the bottom of the menu and tap About.
  3. Tap the Build number 7 times.
  4. Return to the Settings menu and tap Developer options.
  5. Enable ADB debugging.
  6. Connect the watch to your computer and tap Always allow from this computer. (You may need to turn ADB debugging off and then on before the watch prompts you to always allow ADB debugging from the connected computer.)
  7. Use the following adb command to start the watch in fastboot mode: adb reboot bootloader
  8. Optionally, use the following command to lock the watch's bootloader: fastboot oem lock
  9. On the watch, continue the boot as follows: Confirm that Reboot is chosen and long-press the physical button.

After you complete the instructions to set up a phone, your watch will be ready for you to install and run your app.

Set up a phone

On a phone, follow the instructions in this section to install a Wear companion app on an Android or iOS phone. Then pair the watch to the phone.

Download and install the Wear companion app

Confirm that the companion app on your phone is up-to-date.

For example, on the Play Store on an Android phone, go to the Wear OS app listing. Tap Update to download and install the app. After installation, confirm that Auto-update is selected for the app (see the "Set up automatic updates for specific apps" section of Update downloaded apps). Tap Open to start the app.

On the App Store on an iOS phone, go to the Wear OS app listing. Ensure it is up-to-date.

Pair the phone to the watch

After you install a Wear companion app on a phone, unpair ("Forget") any obsolete watch pairings, if necessary. Then you can pair the phone to a newly-imaged watch:

  1. On the phone, select your watch name from the list of watches. A pairing code is displayed on the phone and on the watch. Ensure that the codes match.
  2. Tap Pair to continue the pairing process. When the watch is connected to the phone, a confirmation message is displayed. On the phone, a screen is displayed that lists the accounts on the phone.
  3. Choose a Google Account to add and sync to your watch.
  4. Confirm the screen lock and enter the password to start the copying of the account from the phone to the watch.
  5. Follow the instructions in the wizard to finish the pairing process.

You can begin testing your app with the preview.

Install and run your app

  1. Open your app in Android Studio.
  2. Select your Wear app module name from the Run/Debug configuration drop-down menu (typically wear).
  3. Click the Play button.
  4. In the Select Deployment Target box, click your watch.

After your app is installed on the watch, the app should run.

Note: For more information about creating and running a Wear OS app, see Create a Wear app.

When testing is completed, follow the steps to remove the preview.

Remove the preview from a watch

When testing with the preview is done, unpair ("Forget") the watch from the phone and restore it as follows:

  1. Download and unzip the system image from the "Non-preview image" row in the table above.
  2. Manually flash the image to the watch using steps similar to those to transfer the image to the watch, except that you flash the non-preview image to the watch.

Note: Removing a preview system image requires a full watch reset and removes all user data on the watch.

Set up an emulator

To test with the Android emulator, confirm that you have the latest version of the SDK Platform and SDK Tools from the SDK Manager.

After you create a virtual device as described below, follow the steps to set up a phone.

Create a new virtual device in Android Studio as follows:

  1. Open the AVD Manager by selecting Tools > Android > AVD Manager.
  2. Click Create Virtual Device.
  3. In the Category pane, select Wear and choose a hardware profile. The Wear OS Developer Preview is currently optimized for round devices only, so we recommend you select one of the 'Wear OS Round' profiles. Click Next.
  4. Select a P image to download. The images may be on the x86 tab instead of the Recommended tab, until installed. For example, select the image with the Release Name of "P", the API Level of "P", and the Target of "Android API P (Wear OS)". When the download and installation are complete, click Finish and then click Next.
  5. Verify the configuration of the Android Virtual Device (AVD) and click Finish.
  6. Start the emulator by selecting the new virtual device, clicking the Play button, and waiting until the emulator initializes and shows the Android Wear home screen.

Pair the phone with the emulator, and sync a Google Account, as follows:

  1. Follow the steps to set up a phone.
  2. On the phone, enable Developer Options and USB Debugging.
  3. Connect the phone to your computer through USB.
  4. Forward the AVD's communication port to the connected handheld device (each time the phone is connected):
    adb -d forward tcp:5601 tcp:5601
  5. On the phone, in the Wear app, begin the standard pairing process. For example, on the Welcome screen, tap the Set It Up button. Alternatively, if an existing watch already is paired, in the upper-left drop-down, tap Add a New Watch.
  6. On the phone, in the Wear app, tap the Overflow button, and then tap Pair with Emulator.
  7. Tap the Settings icon.
  8. Under Device Settings, tap Emulator.
  9. Tap Accounts and select a Google Account, and follow the steps in the wizard to sync the account with the emulator. If necessary, type the screen-lock device password, and Google Account password, to start the account sync.

You can now test an app with a virtual preview device in the Android emulator. For information about using virtual devices, see Create and manage virtual devices.

Wear OS for China developer preview

You can use the China developer preview system image in this section for creating and testing Wear apps for the Chinese market (only). The image is for the Huawei Watch 2 Bluetooth watch.

Warning: Installing the system images below on a watch removes all data from the watch. You should backup your data first.

These images generally are used the way the standard Wear images, described above, are used. Download the preview system image below and manually flash it to your test watch. As described below, when testing is completed, you can restore the watch with the China non-preview image below.

China developer preview: image for Huawei Watch 2 Bluetooth

Caution: Flashing your watch will require unlocking the bootloader which shall void the watch's warranty—proceed at your own risk.

Warning: The image below is only for developing apps for the Wear OS China developer preview.

To restore your watch to its original state (the retail image), flash the non-preview image, below, to the watch.

Type of China Huawei Watch 2 system image Download/Checksums
China Developer Preview image for testing sawfish_sw-PWH1.180318.006.tgz
MD5: 6c40593fb98396fd1768efc9571bc0c4
SHA-1: dc4dcef50d9b78352c62bbcd2c964af9780ea98e
China Non-preview image (for after testing) sawfish_sw-factory-OWDD.180215.018.tgz
MD5: e2b5328fed6719a67b6d84c644855b43
SHA-1: 0f0b0331a6793299cbea39052fd9cf183baf88ef
This site uses cookies to store your preferences for site-specific language and display options.

Get the latest Android developer news and tips that will help you find success on Google Play.

* Required Fields

Hooray!

Follow Google Developers on WeChat

Browse this site in ?

You requested a page in , but your language preference for this site is .

Would you like to change your language preference and browse this site in ? If you want to change your language preference later, use the language menu at the bottom of each page.

This class requires API level or higher

This doc is hidden because your selected API level for the documentation is . You can change the documentation API level with the selector above the left navigation.

For more information about specifying the API level your app requires, read Supporting Different Platform Versions.

Take a short survey?
Help us improve the Android developer experience. (April 2018 — Developer Survey)