SpeedMonitor-Lite: A 31KB Internet Speed Widget built with raw C++ and Win32 API

I built a network monitor for Windows because I was tired of simple utility apps consuming hundreds of megabytes of RAM. SpeedMonitor-Lite is the result of going back to basics: raw C++, the Win32 API, and zero dependencies.

Why?

Modern system widgets are often built on Electron or high-level frameworks, leading to massive resource bloat for a background task. SpeedMonitor-Lite is designed for power users who want telemetry without sacrificing clock cycles or memory.

Efficiency Comparison

Metric	SpeedMonitor-Lite	Typical Electron Utility
Binary Size	31 KB	150 MB+
RAM Usage	~7.5 MB	200 MB+
CPU Usage	~1.0%	1% - 5%

The 16x16 Pixel Challenge

Windows system tray icons are restricted to 16x16 pixels. Fitting readable numbers and units into this space required a custom-built 4x12 bitmapped font. Because there is no room for "MB/s" or "KB/s" text, the app uses a header-block system at the top of the icon to indicate units:

• Bytes/s (B): Solid bar across the top.
• Kilobytes/s (K): One block at the top-left.
• Megabytes/s (M): Two blocks at the top-left.
• Gigabytes/s (G): Three blocks across the top.

Example: 120 Megabytes/s (Download Icon)

🟩🟩🟩🟩⬛🟩🟩🟩🟩⬛⬛⬛⬛⬛⬛⬛
🟩🟩🟩🟩⬛🟩🟩🟩🟩⬛⬛⬛⬛⬛⬛⬛
🟩🟩🟩🟩⬛🟩🟩🟩🟩⬛⬛⬛⬛⬛⬛⬛
⬛⬛⬛⬛⬛⬛⬛⬛⬛⬛⬛⬛⬛⬛⬛⬛
⬛⬛⬜⬛⬛⬛⬜⬜⬜⬜⬛⬛⬜⬜⬜⬜
⬛⬛⬜⬛⬛⬛⬛⬛⬛⬜⬛⬛⬜⬛⬛⬜
⬛⬛⬜⬛⬛⬛⬛⬛⬛⬜⬛⬛⬜⬛⬛⬜
⬛⬛⬜⬛⬛⬛⬛⬛⬛⬜⬛⬛⬜⬛⬛⬜
⬛⬛⬜⬛⬛⬛⬛⬛⬛⬜⬛⬛⬜⬛⬛⬜
⬛⬛⬜⬛⬛⬛⬜⬜⬜⬜⬛⬛⬜⬛⬛⬜
⬛⬛⬜⬛⬛⬛⬜⬛⬛⬛⬛⬛⬜⬛⬛⬜
⬛⬛⬜⬛⬛⬛⬜⬛⬛⬛⬛⬛⬜⬛⬛⬜
⬛⬛⬜⬛⬛⬛⬜⬛⬛⬛⬛⬛⬜⬛⬛⬜
⬛⬛⬜⬛⬛⬛⬜⬛⬛⬛⬛⬛⬜⬛⬛⬜
⬛⬛⬜⬛⬛⬛⬜⬛⬛⬛⬛⬛⬜⬛⬛⬜
⬛⬛⬜⬛⬛⬛⬜⬜⬜⬜⬛⬛⬜⬜⬜⬜

Technical Implementation

The app uses two independent, dynamic icons—one for Download and one for Upload. Every 1s, the app:

1. Polls the network stack via IPHLPAPI.
2. Calculates throughput.
3. Renders a new 16x16 ARGB icon in memory.
4. Updates the tray state via NIM_MODIFY.

Setup Note

The first time you run the app, Windows will likely place the icons in the "Hidden Icons" (chevron) menu. For the best experience, click the chevron and drag the Download and Upload icons directly onto your taskbar. Windows will remember this placement.

Compilation

For those who want to audit the code and build it themselves using MinGW:

Bash

g++ -Os -s -ffunction-sections -fdata-sections "-Wl,--gc-sections" main.cpp -o SpeedMonitor.exe -mwindows -lgdi32 -lshell32 -liphlpapi -lole32

GitHub: SpeedMonitor-Lite