iperf3-gui

A Flutter-based Android GUI wrapper for iperf3, the popular network performance measurement tool.

Features

• Client-mode network throughput testing
• Configurable server, port, duration and parallel streams
• Live iperf3 output, streamed line by line while the test runs
• Stop a running test early
• Copy the transcript to the clipboard
• iperf3 3.19 compiled into the app as a native library — no external binary

Architecture

lib/
├── domain/
│   ├── models/          # TestConfiguration, Iperf3Result
├── data/
│   └── services/        # Iperf3Service (MethodChannel → JNI)
├── ui/
│   └── features/
│       └── test_run/    # TestRunScreen, TestRunViewModel
└── main.dart            # App entry point

android/app/src/main/
├── kotlin/…/IperfRunner.kt   # MethodChannel handler, runs tests off the platform thread
└── cpp/iperf_jni.c           # JNI bridge into the iperf3 API

See docs/README.md for the data flow, the native API surface and the design decisions behind them.

Why JNI instead of executing a binary

Android SELinux in Enforcing mode blocks execve() from the untrusted_app domain, so shipping an iperf3 ELF in assets and running it via Process.start() fails with "Permission denied". iperf3 is therefore compiled as a shared library (libiperf3jni.so) and called in-process over JNI.

assets/iperf3/ still holds the pre-compiled binaries from that earlier approach. They are not declared in pubspec.yaml, so they are not packaged into the APK, and nothing in the app reads them.

Building

Prerequisites:

• Flutter 3.47+
• Android SDK with platform android-36
• JDK 17
• NDK r28+ and CMake 3.22.1 (for the native build)

flutter pub get
flutter analyze
flutter test
flutter build apk --debug
adb install -r build/app/outputs/flutter-apk/app-debug.apk

Testing against a local server

iperf3 -s -p 5201                 # on a machine on the same network
ip -4 addr show                   # note its address

Enter that address in the app, then press GO.

Dependencies

• Dart: provider
• Native: iperf3 3.19 + cJSON, built by CMake for armeabi-v7a and arm64-v8a

License

MIT — bundled iperf3 3.19 is BSD-3-Clause licensed.