Timothy Murphy

ChillMac - Free fan control and system monitor for your Mac

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ChillMac is a free, open-source macOS menu bar app that puts fan control and live system monitoring one click from your menu bar. See real-time fan RPM, override fan speeds with manual sliders or Low/Medium/High/Max performance modes, and track CPU, memory, battery, disk, and temperature sensors in clean SwiftUI dashboards. Works on Apple Silicon and Intel Macs. Signed, notarized, and MIT licensed — no account, no telemetry, no paywalls.

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Timothy Murphy
Hey Product Hunt! I built ChillMac because every time my MacBook started sounding like a hair dryer, I had to bounce between iStat Menus, Macs Fan Control, and Activity Monitor to figure out what was actually going on. The Mac fan control apps I liked were either paid, abandoned, or both. So I built the one I wanted — free, open source, and focused. ChillMac lives in your menu bar and gives you: • Live fan RPM in the menu bar at a glance • Per-fan manual speed sliders + Low/Medium/High/Max performance modes • CPU monitor — usage graph, top consuming apps, temperature, uptime • Memory monitor — donut chart, pressure, swap, top consumers • Battery monitor — charge, health %, cycle count, temperature • Disk monitor — storage by category (Apps, Downloads, Documents…) + SSD temp • Color-coded temperature sensors for CPU, GPU, DRAM, SSD, battery, and more • Apple Silicon and Intel support • Auto-update via GitHub releases Under the hood it's a two-process design: an unprivileged SwiftUI app reads SMC sensors directly via IOKit, and a tiny privileged helper (installed via SMAppService) handles fan writes over XPC after validating the caller's code signature. On Apple Silicon it uses SMC test mode to bypass thermalmonitord for manual control, with signal handlers that reset fans to auto on quit or crash. Hardened runtime, signed, notarized, stapled. It's 100% free with no ads, no accounts, no telemetry, and the source is on GitHub under MIT — fork it, hack on it, ship a PR. Download the DMG from the GitHub release, drag to Applications, and it appears in your menu bar. Would love your feedback — especially which sensor or panel you'd want to see next, and whether the performance-mode curves feel right on your machine.
Saul Fleischman

@idevtim This is a solid solution to a real pain point — the fragmentation of Mac system monitoring tools is genuinely annoying. The two-process architecture with code signature validation shows you've thought about security properly, which matters for privileged system access.

Timothy Murphy

@osakasaul Really appreciate that, means a lot. Manual fan control on Apple Silicon has been surprisingly stable so far and I’ve built in safeguards so fans always go back to auto if anything exits or crashes. I’m still fine tuning the fan curves and would love any feedback, so if you get a chance to try it I’d really appreciate it.