Alert

Alert is the core API for native dialogs. Alert.alert(title, message, buttons, options) shows the platform’s own dialog, UIAlertController on iOS and an AlertDialog on Android, so it matches system styling and dark mode without any work.

Alert.alert('Delete project?', 'This cannot be undone.', [
  { text: 'Cancel', style: 'cancel' },
  { text: 'Delete', style: 'destructive', onPress: deleteProject },
]);

Behaviour differs per platform more than the one-line API suggests:

• Button styles cancel and destructive affect presentation on iOS (bold, red). Android ignores them.
• Button count: Android shows at most three buttons (neutral, negative, positive). Extra ones are dropped.
• Dismissal: on Android the user can tap outside or press back if you pass { cancelable: true }, and onDismiss tells you it happened. iOS alerts can only be closed with a button.
• Alert.prompt, which asks for text input, exists on iOS only.

Alert.alert is fire-and-forget: it returns immediately rather than waiting for the user. If you want await confirm(), wrap it in a Promise that resolves from each button’s onPress.

const confirm = (title) =>
  new Promise((resolve) =>
    Alert.alert(title, undefined, [
      { text: 'Cancel', style: 'cancel', onPress: () => resolve(false) },
      { text: 'OK', onPress: () => resolve(true) },
    ]),
  );

The common gotcha is cross-platform reach. On React Native Web, Alert does nothing at all, so a confirmation that guards a destructive action silently disappears. Wrap it in your own helper with a web fallback.

For anything beyond a short question, such as custom layout, images, forms or branded styling, build a Modal or bottom sheet instead. Alerts work best when they are rare, short and native.