// Privacy

Privacy Policy

Effective 7 May 2026 · Last updated 7 May 2026

Short version. Heatsink reads thermal sensors on your Mac and renders them on screen. It does not collect any personal data, does not transmit anything anywhere, and has no network access. There is nothing else to disclose. The long version below is required by Apple and various privacy regulations — it says the same thing in more words.

1. Who this policy applies to

This policy describes how the macOS application Heatsink (the "app") and the website heatsink.uk (the "site") handle information. It applies to anyone who installs the app or visits the site.

2. What the app collects

Nothing. Heatsink does not collect, store, or transmit any personally identifiable information. Specifically, the app does not handle:

Names, email addresses, phone numbers, or contact details
Account credentials or authentication tokens
Location data of any kind (no GPS, no IP-based location, no Wi-Fi/Bluetooth-based location)
Photos, files, contacts, calendars, or any other user content
Browsing history, search queries, or app usage patterns
Device identifiers (no IDFA, no IDFV, no MAC address, no UUID)
Crash logs, diagnostics, or performance telemetry sent to us
Advertising or marketing data

3. What the app reads locally (and never transmits)

Heatsink reads the following from your Mac to render its dashboard. All of these are read locally and stay on your Mac — none of this data is ever sent off-device:

Temperature sensor values via Apple's IOHIDEventSystemClient framework (e.g. die temperatures, battery temperature)
OS thermal pressure state via ProcessInfo.thermalState
CPU and memory utilisation via Mach host_statistics and host_statistics64
Hardware identification — model name, chip name, CPU core count, total RAM, and macOS version, read locally via sysctl and IORegistry

4. What the app stores locally

Heatsink saves your preferences (selected theme, alert threshold, menu-bar options, °C/°F preference) to the standard macOS UserDefaults store inside the app's sandboxed container. These preferences never leave your Mac. The app also keeps a rolling in-memory ring buffer of up to one hour of sensor readings for the sparkline chart and CSV export feature; this buffer is discarded when you quit the app.

5. CSV export

If you choose to export your local sensor history to CSV via Settings → Export, the file is saved wherever you tell macOS to put it via the Save panel. Heatsink does not upload, share, or otherwise transmit the exported file. What happens to it after that is entirely under your control.

6. Notifications

If you enable threshold alerts, Heatsink schedules local notifications via Apple's UNUserNotificationCenter. These notifications are generated and displayed entirely on your Mac. No notification content is sent to any server, including ours.

7. Network activity

Heatsink does not make any network connections of its own. It is sandboxed and does not request the network-client entitlement. macOS itself may communicate with Apple servers for receipt validation and notarisation when you install the app — that is between you, your Mac, and Apple, and is governed by Apple's privacy policy.

8. Third-party services

Heatsink does not embed any third-party SDKs, analytics frameworks, advertising networks, crash reporters, or trackers. There are no third-party services with which we share any data, because there is no data being collected to share.

9. The website (heatsink.uk)

The website is a static set of HTML pages hosted on Cloudflare Pages. We do not run any analytics, cookies, or tracking scripts. Cloudflare's edge infrastructure logs basic HTTP request information (IP address, user agent, timestamp, requested URL) for a short period for security and abuse prevention. We do not access or use these logs for any other purpose. See Cloudflare's privacy policy for their handling.

10. Children

Heatsink is a developer/system utility and is not directed at children under 13. We do not knowingly collect data from children because we do not knowingly collect data from anyone.

11. Your rights (GDPR, CCPA, and friends)

Privacy regulations such as the EU's GDPR, the UK's UK-GDPR, and California's CCPA grant you rights to access, correct, or delete personal information held about you. Because Heatsink does not collect, store, or process personal data, these rights are substantively satisfied by default — there is nothing for us to access, correct, or delete on your behalf. If you have questions, you can still contact us at the address below.

12. Changes to this policy

If this policy changes — for example, if a future version of the app introduces optional data handling — we will update the "Last updated" date at the top of this page. Material changes will be summarised at the top of the next app release notes.

13. Contact

For privacy-related questions, email [email protected].

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