Apps / Not a Fan
System · Thermals

Not a Fan

CPU temperature and fan speed, always visible.

Not a Fan keeps the current CPU temperature in your menu bar and tells you when the chip is being thermally throttled. Works on both Intel and Apple Silicon, and gracefully handles fanless Macs.

Download for Mac View source
Free·macOS 11+·v1.0.1

What it does

01

Live temperature

CPU package temperature in the menu bar, updated continuously. The font is monospaced so the digits don't jitter.

02

Per-fan RPM

Each fan's current RPM in the dropdown — useful when you want to know whether the system is actually moving air.

03

Throttle alerts

Native banner the moment the SMC reports CPU thermal throttling. Subscribe-based via go-pmset — no polling cost.

04

Apple Silicon ready

Reads SMC sensors via go-smc, which supports M1 / M2 / M3 / M4 alongside Intel.

05

Fanless Mac aware

MacBook Air, Mac mini base, Mac Studio show “No fans!” rather than a stuck zero.

06

Set and forget

Launches at login; updates from GitHub releases.

Built with menuet

Not a Fan is open source.

It’s a few hundred lines of Go on top of menuet — the same library you can use to build your own menu‑bar app. Read the source, or start your own.

Build your own → Read the source
// caseymrm/notafan
import "github.com/caseymrm/menuet/v2"