CPU Indicator

A tiny Windows 10 / 11 tray icon that shows CPU usage, so you can check it at a glance without opening Task Manager.

• Small: a ~60 KB native exe with no runtime to install. It uses about 4 MB of RAM while running.
• Matches Task Manager: it reads the same % Processor Utility counter Task Manager uses.
• Four styles: a number, a coloured square, a coloured circle, or a mini graph of the last 8 readings.
• Sharp at any scale: the icon is drawn at the size Windows asks for, so it stays crisp at 125%, 150% and 200%.
• Follows your theme: the number turns black or white to suit a light or dark taskbar. The settings window follows Windows light/dark mode and accent colour.

Download

Get CPU-Indicator.exe from the latest release. There's nothing to install: put it somewhere permanent (for example C:\Utilities) and run it. Windows SmartScreen may warn the first time, because the exe isn't code-signed. Choose More info › Run anyway.

Using it

• Left-click the tray icon to open settings. Right-click for Settings, Start with Windows and Exit.
• Hover over the icon to see the exact percentage.
• Running the exe again while it's already running opens settings.
• On Windows 11, new tray icons start in the hidden-icons overflow (^). To keep it on the taskbar, drag it out, or turn it on under Settings › Personalisation › Taskbar › Other system tray icons.

Settings are saved in HKCU\Software\CPU Indicator. "Start with Windows" adds a CPU Indicator entry under HKCU\...\CurrentVersion\Run.

Why it might differ from Task Manager

The two sample at slightly different moments, so on a spiky load one can catch a burst the other misses. Both show whole numbers. The icon shows at most 99, because three digits don't fit at tray size; the tooltip shows the real value.

Building

Needs MinGW-w64 GCC, for example:

winget install BrechtSanders.WinLibs.POSIX.UCRT

Then run build.bat. The output is build\CPU Indicator.exe.

To publish a release, add notes in docs/releases/vX.Y.Z.md (optional), then push a tag: git tag vX.Y.Z and git push origin vX.Y.Z. GitHub Actions builds the exe and creates the release.

File	What it does
src/main.cpp	Tray icon, timer, right-click menu, single instance
src/cpu.cpp	Reads CPU usage through PDH
src/indicator.cpp	Draws the number, square, circle or graph
src/settings_window.cpp	The settings window, drawn by hand in the Windows 11 style
src/settings.cpp	Saves settings to the registry; Start with Windows
tools/make-icon.ps1	Regenerates res/app.ico