File: constants.md | Updated: 11/15/2025
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An API that provides system information that remains constant throughout the lifetime of your app's installation.
Android
iOS
tvOS
Web
Bundled version:
~17.1.7
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expo-constants provides system information that remains constant throughout the lifetime of your app's installation.
Terminal
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- npx expo install expo-constants
If you are installing this in an existing React Native app
, make sure to install expo
in your project.
import Constants from 'expo-constants';
AndroidManifestOnly for:
Android
Type: Record<string, any> extended by:
| Property | Type | Description |
| --- | --- | --- |
| versionCode | number | > Deprecated Use expo-application's Application.nativeBuildVersion<br>> .<br><br>The version code set by android.versionCode in app.json. The value is set to null in case you run your app in Expo Go. |
ClientScopingConfigType: [ClientScopingConfigForReExport](https://docs.expo.dev/versions/v53.0.0/sdk/manifests#clientscopingconfigforreexport)
EASConfigType: [ManifestsEASConfig](https://docs.expo.dev/versions/v53.0.0/sdk/manifests#manifestseasconfig)
ExpoGoConfigType: [ManifestsExpoGoConfig](https://docs.expo.dev/versions/v53.0.0/sdk/manifests#manifestsexpogoconfig)
ExpoGoPackagerOptsType: [ExpoGoPackagerOptsForReExport](https://docs.expo.dev/versions/v53.0.0/sdk/manifests#expogopackageroptsforreexport)
IOSManifestOnly for:
iOS
Type: Record<string, any> extended by:
| Property | Type | Description |
| --- | --- | --- |
| buildNumber | string \| null | The build number specified in the embedded Info.plist value for CFBundleVersion in this app. In a standalone app, you can set this with the ios.buildNumber value in app.json. This may differ from the value in Constants.expoConfig.ios.buildNumber because the manifest can be updated, whereas this value will never change for a given native binary. The value is set to null in case you run your app in Expo Go. |
| model | string \| null | > Deprecated Moved to expo-device as Device.modelName<br>> .<br><br>The human-readable model name of this device. For example, "iPhone 7 Plus" if it can be determined, otherwise will be null. |
| platform | string | > Deprecated Use expo-device's Device.modelId<br>> .<br><br>The Apple internal model identifier for this device.<br><br>Example<br><br>iPhone1,1 |
| systemVersion | string | > Deprecated Use expo-device's Device.osVersion<br>> .<br><br>The version of iOS running on this device.<br><br>Example<br><br>10.3 |
| userInterfaceIdiom | [UserInterfaceIdiom](https://docs.expo.dev/versions/v53.0.0/sdk/constants#userinterfaceidiom) | > Deprecated Use expo-device's Device.getDeviceTypeAsync()<br>> .<br><br>The user interface idiom of the current device, such as whether the app is running on an iPhone, iPad, Mac or Apple TV. |
ManifestType: [ExpoUpdatesManifest](https://docs.expo.dev/versions/v53.0.0/sdk/manifests#expoupdatesmanifest)
ManifestAssetType: [ManifestAssetForReExport](https://docs.expo.dev/versions/v53.0.0/sdk/manifests#manifestassetforreexport)
ManifestExtraType: [ManifestExtraForReExport](https://docs.expo.dev/versions/v53.0.0/sdk/manifests#manifestextraforreexport)
NativeConstantsType: Record<string, any> extended by:
| Property | Type | Description |
| --- | --- | --- |
| appOwnership | [AppOwnership](https://docs.expo.dev/versions/v53.0.0/sdk/constants#appownership) \| null | > Deprecated Use Constants.executionEnvironment<br>> instead.<br><br>Returns expo when running in Expo Go, otherwise null. |
| debugMode | boolean | Returns true when the app is running in debug mode (__DEV__). Otherwise, returns false. |
| deviceName(optional) | string | A human-readable name for the device type. |
| deviceYearClass | number \| null | > Deprecated Moved to expo-device as Device.deviceYearClass<br>> .<br><br>The device year class<br> of this device. |
| easConfig | [ManifestsEASConfig](https://docs.expo.dev/versions/v53.0.0/sdk/manifests#manifestseasconfig) \| null | The standard EAS config object populated when using EAS. |
| executionEnvironment | [ExecutionEnvironment](https://docs.expo.dev/versions/v53.0.0/sdk/constants#executionenvironment) | Returns the current execution environment. |
| experienceUrl | string | - |
| expoConfig | [ExpoConfig](https://github.com/expo/expo/blob/main/packages/%40expo/config-types/src/ExpoConfig.ts) & { hostUri: string } \| null | The standard Expo config object defined in app.json and app.config.js files. For both classic and modern manifests, whether they are embedded or remote. |
| expoGoConfig | [ManifestsExpoGoConfig](https://docs.expo.dev/versions/v53.0.0/sdk/manifests#manifestsexpogoconfig) \| null | The standard Expo Go config object populated when running in Expo Go. |
| expoRuntimeVersion | string \| null | Nullable only on the web. |
| expoVersion | string \| null | The version string of the Expo Go app currently running. Returns null in bare workflow and web. |
| getWebViewUserAgentAsync | () => [Promise](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Promise) <string \| null> | Gets the user agent string which would be included in requests sent by a web view running on this device. This is probably not the same user agent you might be providing in your JS fetch requests. |
| intentUri(optional) | string | - |
| isDetached(optional) | boolean | - |
| isHeadless | boolean | Returns true if the app is running in headless mode. Otherwise, returns false. |
| linkingUri | string | - |
| manifest2 | [ExpoUpdatesManifest](https://docs.expo.dev/versions/v53.0.0/sdk/manifests#expoupdatesmanifest) \| null | Manifest for Expo apps using modern Expo Updates from a remote source, such as apps that use EAS Update. Constants.expoConfig should be used for accessing the Expo config object. |
| platform(optional) | [PlatformManifest](https://docs.expo.dev/versions/v53.0.0/sdk/constants#platformmanifest) | Returns the specific platform manifest object.<br><br>> Note: This is distinct from the manifest and manifest2. |
| sessionId | string | A string that is unique to the current session of your app. It is different across apps and across multiple launches of the same app. |
| statusBarHeight | number | The default status bar height for the device. Does not factor in changes when location tracking is in use or a phone call is active. |
| systemFonts | string[] | A list of the system font names available on the current device. |
| systemVersion(optional) | number | - |
PlatformManifestType: Record<string, any> extended by:
| Property | Type | Description |
| --- | --- | --- |
| android(optional) | [AndroidManifest](https://docs.expo.dev/versions/v53.0.0/sdk/constants#androidmanifest) | - |
| detach(optional) | { scheme: string } | - |
| developer(optional) | string | - |
| hostUri(optional) | string | - |
| ios(optional) | [IOSManifest](https://docs.expo.dev/versions/v53.0.0/sdk/constants#iosmanifest) | - |
| scheme(optional) | string | - |
| web(optional) | [WebManifest](https://docs.expo.dev/versions/v53.0.0/sdk/constants#webmanifest) | - |
WebManifestOnly for:
Web
Type: Record<string, any>
AppOwnershipDeprecated Use
Constants.executionEnvironmentinstead.
ExpoAppOwnership.Expo ＝ "expo"
The experience is running inside the Expo Go app.
ExecutionEnvironmentBareExecutionEnvironment.Bare ＝ "bare"
StandaloneExecutionEnvironment.Standalone ＝ "standalone"
StoreClientExecutionEnvironment.StoreClient ＝ "storeClient"
UserInterfaceIdiomCurrent supported values are handset, tablet, desktop and tv. CarPlay will show up as unsupported.
DesktopUserInterfaceIdiom.Desktop ＝ "desktop"
HandsetUserInterfaceIdiom.Handset ＝ "handset"
TabletUserInterfaceIdiom.Tablet ＝ "tablet"
TVUserInterfaceIdiom.TV ＝ "tv"
UnsupportedUserInterfaceIdiom.Unsupported ＝ "unsupported"