---
uid: Uno.Features.WS
---

# URI Launcher

> [!TIP]
> This article covers Uno-specific information for the `Windows.System` namespace. For a full description of the feature and instructions on using it, see [Windows.System Namespace](https://learn.microsoft.com/uwp/api/windows.system).

* The `Windows.System.Launcher` class provides functionality for launching URIs and apps.

## `LaunchUriAsync`

This API is supported on iOS, Android, WASM, and macOS.

On iOS, Android, and macOS the `ms-settings:` special URI is supported.

### Platform-specifics

On iOS, launching the special URI opens the main page of system settings because deep-linking to specific settings is not available.

For WASM, launching the special URI will work properly only when opening the website on Windows. The method will return `true` even if the user cancels the application launch, as there is currently no way to detect if the app was successfully launched. When using `LaunchUriAsync` on WASM, note that there should be no await between user interaction (button click / command etc) and the Launcher invocation. Otherwise, the browser may ignore it due to security reasons.

In case of Android, we support the following nested URIs.

| Settings URI | Android Mapping |
|--------------|----------|
| `ms-settings:sync` | `Settings.ActionSyncSettings` |
| `ms-settings:appsfeatures-app` | `Settings.ActionApplicationDetailsSettings` |
| `ms-settings:appsfeatures` | `Settings.ActionApplicationSettings` |
| `ms-settings:defaultapps` | `Settings.ActionManageDefaultAppsSettings` |
| `ms-settings:appsforwebsites` | `Settings.ActionManageDefaultAppsSettings` |
| `ms-settings:cortana` | `Settings.ActionVoiceInputSettings` |
| `ms-settings:bluetooth` | `Settings.ActionBluetoothSettings` |
| `ms-settings:printers` | `Settings.ActionPrintSettings` |
| `ms-settings:typing` | `Settings.ActionHardKeyboardSettings` |
| `ms-settings:easeofaccess` | `Settings.ActionAccessibilitySettings` |
| `ms-settings:network-airplanemode` | `Settings.ActionAirplaneModeSettings` |
| `ms-settings:network-celluar` | `Settings.ActionNetworkOperatorSettings` |
| `ms-settings:network-datausage` | `Settings.ActionDataUsageSettings` |
| `ms-settings:network-wifiSettings` | `Settings.ActionWifiSettings` |
| `ms-settings:nfctransactions` | `Settings.ActionNfcSettings` |
| `ms-settings:network-vpn` | `Settings.ActionVpnSettings` |
| `ms-settings:network-wifi` | `Settings.ActionWifiSettings` |
| `ms-settings:network` | `Settings.ActionWirelessSettings` |
| `ms-settings:personalization` | `Settings.ActionDisplaySettings` |
| `ms-settings:privacy` | `Settings.ActionPrivacySettings` |
| `ms-settings:about` | `Settings.ActionDeviceInfoSettings` |
| `ms-settings:apps-volume` | `Settings.ActionSoundSettings` |
| `ms-settings:batterysaver` | `Settings.ActionBatterySaverSettings` |
| `ms-settings:display` | `Settings.ActionDisplaySettings` |
| `ms-settings:screenrotation` | `Settings.ActionDisplaySettings` |
| `ms-settings:quiethours` | `Settings.ActionZenModePrioritySettings` |
| `ms-settings:quietmomentshome` | `Settings.ActionZenModePrioritySettings` |
| `ms-settings:nightlight` | `Settings.ActionNightDisplaySettings` |
| `ms-settings:taskbar` | `Settings.ActionDisplaySettings` |
| `ms-settings:notifications` | `Settings.ActionAppNotificationSettings` |
| `ms-settings:storage` | `Settings.ActionInternalStorageSettings` |
| `ms-settings:sound` | `Settings.ActionSoundSettings` |
| `ms-settings:dateandtime` | `Settings.ActionDateSettings` |
| `ms-settings:keyboard` | `Settings.ActionInputMethodSettings` |
| `ms-settings:regionlanguage` | `Settings.ActionLocaleSettings` |
| `ms-settings:developers` | `Settings.ActionApplicationDevelopmentSettings` |

In case of macOS, Uno supports the following nested URIs, mapped to Preference Panes (/System/Library/PreferencePanes)

| Settings URI | macOS Mapping |
|--------------|----------|
| `ms-settings:signinoptions-launchfaceenrollment` | `TouchID` |
| `ms-settings:launchfingerprintenrollment` | `TouchID` |
| `ms-settings:signinoptions` | `Accounts` |
| `ms-settings:emailandaccounts` | `InternetAccounts` |
| `ms-settings:appsforwebsites` | `Settings.ActionManageDefaultAppsSettings` |
| `ms-settings:tabletmode` | `Expose` |
| `ms-settings:personalization-start` | `Expose` |
| `ms-settings:personalization-background` | `DesktopScreenEffectsPref` |
| `ms-settings:personalization` | `Appearance` |
| `ms-settings:bluetooth` | `Bluetooth` |
| `ms-settings:dateandtime` | `DateAndTime` |
| `ms-settings:region` | `Localization` |
| `ms-settings:typing` | `Keyboard` |
| `ms-settings:display` | `Displays` |
| `ms-settings:screenrotation` | `Displays` |
| `ms-settings:taskbar` | `Dock` |
| `ms-settings:batterysaver` | `EnergySaver` |
| `ms-settings:powersleep` | `EnergySaver` |
| `ms-settings:otherusers` | `FamilySharingPrefPane` |
| `ms-settings:mousetouchpad` | `Mouse` |
| `ms-settings:devices-touchpad` | `Trackpad` |
| `ms-settings:network` | `Network` |
| `ms-settings:privacy-notifications` | `Notifications` |
| `ms-settings:printers` | `PrintAndFax` |
| `ms-settings:privacy` | `Security` |
| `ms-settings:crossdevice` | `SharingPref` |
| `ms-settings:quiethours` | `ScreenTime` |
| `ms-settings:quietmomentshome` | `ScreenTime` |
| `ms-settings:sound` | `Sound` |
| `ms-settings:windowsupdate` | `SoftwareUpdate` |
| `ms-settings:cortana-windowssearch` | `Spotlight` |
| `ms-settings:cortana` | `Speech` |
| `ms-settings:storage` | `StartupDisk` |
| `ms-settings:backup` | `TimeMachine` |
| `ms-settings:easeofaccess` | `UniversalAccessPref` |

### Exceptions

* When the `uri` argument is `null`, `NullReferenceException` is thrown. Note this differs from WinUI, where `AccessViolationException` is thrown.
* When the method is called from a non-UI thread, `InvalidOperationException` is thrown.

Exceptions are in line with WinUI.

## `QueryUriSupportAsync`

This API is supported on iOS, Android, and macOS, and the implementation does not respect the `LaunchQuerySupportType` parameter yet. It also reports the aforementioned special `ms-settings` URIs on Android and iOS as supported.

### Platform-specific requirements

#### Android

When targeting Android 11 (API 30) or newer, you may notice the `QueryUriSupportAsync` returning false. To avoid this, make sure to add any URL schemes passed to it as `<queries>` entries in your `AndroidManifest.xml`:

```xml
<queries>
  <intent>
    <action android:name="android.intent.action.VIEW" />
    <data android:scheme="tel" />
  </intent>

  <intent>
    <action android:name="android.intent.action.VIEW" />
    <category android:name="android.intent.category.DEFAULT" />
    <category android:name="android.intent.category.BROWSABLE" />
    <data android:scheme="https" />
  </intent>
</queries>
```

#### iOS

Add any URL schemes passed to `QueryUriSupportAsync` as `LSApplicationQueriesSchemes` entries in your `Info.plist` file, otherwise, it will return false:

```xml
<key>LSApplicationQueriesSchemes</key>
<array>
  <string>tel</string>
  <string>https</string>
</array>
```

### Exceptions

* When the `uri` argument is `null`, `NullReferenceException` is thrown. Note this differs from WinUI, where a plain `Exception` with HRESULT is thrown.

Exceptions are in line with WinUI.