flutter_performance_monitor_plus #

In-app performance monitor overlay for Flutter. See FPS, frame times, rebuilds, memory (best-effort), CPU, and network requests without leaving your app.

Why #

• Spot jank early with live FPS/build/raster timing overlays.
• Track rebuild churn, memory, and CPU in debug/profile without opening DevTools.
• Capture HTTP traffic automatically (or log manually) alongside UI performance.

Features #

• Draggable bubble with quick stats; tap to expand a detailed panel.
• Double-tap the bubble to dock it to the screen edge (peek handle); tap handle to reveal.
• Long-press bubble or peek handle to open the Flutter performance metrics guide.
• FPS, build/raster times, rebuilds/sec, jank/sec, memory (VM RSS), CPU%, hot reload/restat counters.
• Network logging via MonitoredHttpClient or manual logs.
• Pure Dart/Flutter; works on Android, iOS, web, and desktop.

Install #

Add to pubspec.yaml:

dependencies:
  flutter_performance_monitor_plus: ^0.0.1

Usage #

Wrap your app:

void main() {
  runApp(
    PerformanceMonitorPlus(
      config: const PerformanceMonitorConfig(
        enableNetworkLogging: true,
        expandedByDefault: false,
      ),
      child: const MyApp(),
    ),
  );
}

Attach later to an existing Overlay:

final handle = PerformanceMonitorPlus.attach(
  context,
  config: const PerformanceMonitorConfig(
    overlayPosition: PerformanceOverlayPosition.bottomLeft,
  ),
);
// Call handle.detach() to remove and dispose.

Log network calls with the bundled client:

final client = MonitoredHttpClient();
final response = await client.get(Uri.parse('https://jsonplaceholder.typicode.com/todos/1'));

Or log manually:

PerformanceMonitorPlus.logNetworkRequest(
  method: 'CUSTOM',
  url: 'app://local/step',
  duration: const Duration(milliseconds: 40),
  statusCode: 200,
);

Gestures (bubble) #

• Tap: expand/collapse panel.
• Double-tap: dock to nearest screen edge; tap handle to reveal.
• Long-press: open performance metrics docs (external browser).
• Drag: reposition; releasing snaps back to normal state.

Config options #

const PerformanceMonitorConfig(
  enableFps: true,
  enableFrameTime: true,
  enableRebuildsCount: true,
  enableMemory: true,
  enableNetworkLogging: true,
  overlayPosition: PerformanceOverlayPosition.topRight,
  overlayOpacity: 0.95,
  expandedByDefault: false,
  maxNetworkEntries: 50,
  mode: PerformanceMonitorMode.visible, // hidden keeps collectors running
  theme: PerformanceMonitorThemeData.dark(), // or light() / custom
);

Notes & limits #

• Rebuild counts rely on debugOnRebuildDirtyWidget; they update in debug/profile.
• Memory uses ProcessInfo.currentRss when available; web targets show n/a.
• CPU is best-effort and may be null on some platforms.

Example app #

cd example
flutter run

The sample app shows FPS/rebuild churn via animation, a sample HTTP call, the overlay bubble/panel, and the metrics help link.

Screenshots #

Animated demo (GIF):

Collapsed bubble (peek/edge dock):

Expanded panel: