What is custom tone duration limitation for android and IOS , what will happen custom tone files duration is longer then tone what we have provided?

Overview

Both Android and iOS have strict limitations on custom notification ringtone file durations. If your custom tone file exceeds these limits, the OS falls back to the default system notification sound.

iOS Custom Tone Limitations

.aiff

.wav

.caf

dartCopy
// Flutter Local Notifications — iOS custom sound
NotificationDetails(
  iOS: DarwinNotificationDetails(
    sound: 'custom_tone.aiff', // Must be ≤ 30 seconds, in main bundle
  ),
)

iOS Behavior if duration > 30s: The OS silently ignores the custom tone and plays the default system alert sound instead.

Android Custom Tone Limitations

.mp3

.ogg

.wav

res/raw/

kotlinCopy
// Android — set custom sound on notification channel
val sound = RingtoneManager.getDefaultUri(RingtoneManager.TYPE_NOTIFICATION)
val channel = NotificationChannel(
    "my_channel",
    "My Channel",
    NotificationManager.IMPORTANCE_HIGH
).apply {
    setSound(
        Uri.parse("android.resource://$packageName/raw/custom_tone"),
        AudioAttributes.Builder()
            .setUsage(AudioAttributes.USAGE_NOTIFICATION)
            .build()
    )
}

Flutter Implementation

dartCopy
// flutter_local_notifications package
const AndroidNotificationDetails androidDetails = AndroidNotificationDetails(
  'channel_id',
  'Channel Name',
  sound: RawResourceAndroidNotificationSound('custom_tone'), // no extension
  importance: Importance.high,
  priority: Priority.high,
);

const DarwinNotificationDetails iosDetails = DarwinNotificationDetails(
  sound: 'custom_tone.aiff', // ≤ 30 seconds
);

const NotificationDetails notificationDetails = NotificationDetails(
  android: androidDetails,
  iOS: iosDetails,
);

What Happens If Duration Exceeds Limit?

Best Practices

• ✅ Keep custom tones under 30 seconds (target 2–5 seconds for notifications)
• ✅ Convert iOS sounds to
  textCopy

  .caf

  format for better quality and compatibility
• ✅ Test on actual devices — emulators may behave differently
• ✅ For Android, set the sound at channel creation time — it cannot be changed once the channel exists
• ❌ Do not use long music files as notification sounds