While I couldn't find any officially available free license keys, here are a few alternatives:
While Macs Fan Control Pro is a paid application, there are ways to get a free license key. Here are a few methods: macs fan control pro license key free
deal for users who might be considering an upgrade or are in the process of uninstalling. CrystalIDEA Why Avoid "Free" Pro License Keys? Security Risks While I couldn't find any officially available free
While Macs Fan Control Pro offers a free trial, a license key is required to unlock the full range of features and continue using the software beyond the trial period. A license key provides: macs fan control pro license key free