Answer
An HTML app running in Android WebView cannot run code while closed (background sync, alarms), use Web Push or the Notification API, download files or show PDFs itself, use Web Share, Bluetooth, USB or NFC APIs, or play audio in the background. Most have a workaround: native push from the app shell, opening links in other apps, or a server.
| Not available | Workaround |
|---|---|
| Web Push / Notification API | Native push via the app shell (HTML2APK Pro uses OneSignal) |
| Background tasks and timers | Compute from timestamps when the app reopens; use a server |
| File downloads, PDF viewer | Open the file's https link in the browser; show content as HTML |
| Web Share API | Copy-to-clipboard, or links to share URLs |
| Bluetooth, USB, NFC, Serial | A native app or plugin framework (Capacitor) |
| Background audio | A native media app |
| Vibration | Treat as optional; may be ignored |
Full support details: WebView HTML5 support table.
Frequently asked questions
Can an HTML app send notifications?
Not through the web Notification or Push APIs. The app shell can receive native push notifications if the builder supports it.