Features

• Returns total, available, and used storage in bytes (int / Int64)
• iOS: uses volumeAvailableCapacityForImportantUsage for values that closely align with the Settings > General > iPhone Storage display
• Android: uses StatFs.availableBytes (not freeBytes) to represent user-available storage

Installation

Add to your pubspec.yaml:

dependencies:
  accurate_storage_info: ^0.1.0

Then run:

flutter pub get

Usage

import 'package:accurate_storage_info/storage_info.dart';

Future<void> loadStorage() async {
  final total = await StorageInfo.getTotalBytes();
  final available = await StorageInfo.getAvailableBytes();
  final used = await StorageInfo.getUsedBytes(); // computed as total - available

  double toGiB(int bytes) => bytes / (1024 * 1024 * 1024);

  print('total=$total, available=$available, used=$used');

  print('totalGiB=${toGiB(total).toStringAsFixed(2)}');
  print('availableGiB=${toGiB(available).toStringAsFixed(2)}');
  print('usedGiB=${toGiB(used).toStringAsFixed(2)}');
}

See the example project in example/lib/main.dart.

API

class StorageInfo {
  static Future<int> getTotalBytes();
  static Future<int> getAvailableBytes();
  static Future<int> getUsedBytes(); // computed = total - available
}

All values are returned in bytes.

Platform Details

iOS

The plugin queries the volume backing the app sandbox:

FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!

It uses:

API Key	Meaning
volumeTotalCapacityKey	Total storage capacity
volumeAvailableCapacityForImportantUsageKey	Available storage suitable for user/data workloads
(Fallback) volumeAvailableCapacityKey	Used only when important-available is not positive

used = total - available

If both total and available resolve to 0, the plugin throws a FlutterError.

Rationale:
volumeAvailableCapacityForImportantUsage accounts for purgeable system-managed storage and generally matches the value users see in Settings.

Android

Uses:

val stat = StatFs(Environment.getDataDirectory().path)
total = stat.totalBytes
available = stat.availableBytes

used = total - available

availableBytes reflects user-available storage, whereas freeBytes may include system-reserved space and typically does not match UI expectations.

Repository

GitHub: nvtanhh/accurate_storage_info

Troubleshooting

• If Dart imports fail, run flutter pub get.
• iOS values are most accurate on real devices; the simulator does not represent actual device storage.
• Ensure the app has permission to run normally; no additional storage permissions are required.

License

MIT. See LICENSE.

Changelog

See CHANGELOG.md.