mectrics

What is mectrics?

mectrics is a lightweight, open-source system monitor that lives quietly in your macOS menu bar. Instead of a bulky dashboard or a dock icon you have to check, it puts the numbers you care about—CPU, memory, battery, network, disk, GPU, temperature, and fans—right where you can see them at a glance. You decide which metrics appear, set a threshold for each, and mectrics only speaks up when something is actually off. It's free, MIT-licensed, and designed for macOS 15 and later.

Who it's for

• The minimalism-minded Mac user — you want system stats available instantly, but you don't want a cluttered menu bar or a constant stream of graphs.
• The performance-conscious professional — you need to monitor CPU cores, disk throughput, or GPU load without opening Activity Monitor every few minutes.
• The privacy-focused tinkerer — you appreciate open-source software that runs entirely on-device, with nothing leaving your Mac.

Key features

Menu bar live metrics

mectrics puts the exact numbers you choose directly into your menu bar. Pick from CPU, memory, battery, network, disk, GPU, temperature, and fans—everything else stays out of the way. You set it once, and the display stays clean and unobtrusive.

Click for detail

Every menu bar item opens a popover with the real story behind the number. CPU shows a bar per core, disk displays capacity alongside live throughput, and each metric gives you the context you need to understand what's happening at a glance.

Compact Health mode

Instead of showing multiple items, Compact Health folds your entire machine into a single menu bar entry. It stays quiet and invisible until something crosses your threshold—then it speaks up. This is ideal for users who want monitoring without any visual noise.

Threshold alerts

You set the limits, and mectrics handles the rest. When a metric exceeds your threshold, the app draws attention to it. No constant polling, no background anxiety—just a clear signal when your Mac needs attention.

What stands out

"A system monitor that stays quiet until something's actually wrong."

Most monitoring tools demand your attention constantly. mectrics takes the opposite approach: it's designed to be ignored. The Compact Health feature is the clearest expression of this philosophy—one small item that represents the whole machine, only surfacing when a threshold is crossed. Combined with its tiny 3.8 MB footprint and MIT license, it's a tool that respects both your screen space and your freedom.

Worth checking out if…

You want a free, open-source system monitor that doesn't nag you. If you've tried full-featured monitors and found them overwhelming, or if you simply want a clean menu bar with the few numbers you actually care about, mectrics is worth a look. It's especially appealing if you value privacy (nothing leaves your Mac), prefer minimal UI, and want the ability to drill into details only when you choose to.