WhoLagged is a Windows diagnostic tool that identifies the process or driver responsible for system stuttering, input lag, and performance degradation.
It is designed for situations where Task Manager shows normal CPU, memory, and disk usage, but the system still feels slow or unresponsive.
Modern Windows systems can experience stuttering even when resource usage appears normal.
Typical symptoms include:
- Mouse or keyboard input delay
- Audio crackling or distortion
- Game stuttering despite stable FPS
- Random UI freezes
- System lag with low CPU usage
These issues are often caused by kernel-level scheduling or driver behavior that is not visible in traditional monitoring tools.
WhoLagged analyzes low-level system behavior to identify the most likely cause of lag, including:
- Processes causing excessive CPU scheduling pressure
- Drivers introducing kernel-level latency (DPC activity)
- Disk I/O operations causing hidden delays
It then produces a simple result pointing to the most likely culprit.
Unlike Task Manager or basic performance monitors, WhoLagged focuses on root cause detection rather than resource usage.
Unlike heavy diagnostic tools such as LatencyMon, it provides a simplified and direct result.
The tool will output a diagnosis such as:
- A process causing excessive scheduling load
- A driver responsible for system latency
- Disk-related performance bottleneck
- Or no clear culprit detected
WhoLagged analyzes Windows kernel-level runtime behavior using event-based system telemetry.
It focuses on scheduling patterns, driver execution behavior, and I/O latency signals to detect anomalies that correlate with system stuttering.
All data is processed in real time with minimal overhead.
- Windows 10 / Windows 11 (x64)
- Administrator privileges
- .NET 8 Runtime
Run the executable as Administrator:
WhoLagged.exe
The tool will sample system behavior for a short period and output a diagnosis.
dotnet build -c Release
dotnet publish -c Release -r win-x64 --self-contained true -p:PublishSingleFile=true
GNU GPL-3.0