Privacy policy

Who we are

This policy covers the website heatsink.pro and the heat sink calculator on it, both operated by heatsink.pro (“we”). Questions go to privacy@heatsink.pro.

This website

This website has no forms and no analytics. It sets cookies only if you sign in with GitHub (below). Our hosting provider, Cloudflare, processes standard request data (such as IP addresses) to deliver and protect the site, under its own privacy policy. If you email us, we use your message and address only to reply.

Signing in with GitHub

The calculator is open only to people we have invited. They sign in with their GitHub account. The front page and this policy work without signing in.

What we collect

When you sign in, GitHub tells us your public GitHub username, your numeric GitHub user id and the web address of your public profile picture. We ask GitHub for no permissions beyond your public profile.

What we don’t collect

We do not receive your email address, your password, or access to your repositories, organizations or any other GitHub data. GitHub gives us a temporary access token so that we can read your public profile once; we use it for that single request and do not store it.

Cookies

Signing in sets two cookies, both marked HttpOnly and Secure: a sign-in check cookie, which protects the sign-in against forgery and expires after 10 minutes or when sign-in finishes; and a session cookie holding your GitHub username, user id, profile picture address and an expiry time, signed so that it cannot be altered. It lasts 30 days. We use them only to recognize you and decide whether you have been invited. We use no tracking or advertising cookies.

Where it is kept and for how long

Your sign-in details are kept only in the session cookie in your browser. We keep no account database or server-side copy. The list of invited people is a list of GitHub usernames that we maintain ourselves. The session ends after 30 days, when you sign out, or when you clear your cookies.

Signing out

Use “Sign out” on the home page, or clear this site’s cookies in your browser. To remove the app from your GitHub account entirely, revoke “Heatsink Pro” under Settings → Applications → Authorized OAuth Apps on GitHub. Your use of GitHub itself is covered by GitHub’s privacy statement.

The calculator

What is sent to our server

When you press Solve, and once each time you open the calculator or load a project, your browser sends the inputs of that calculation to our server: the heat sink’s dimensions and materials, the airflow or fan curve, the ambient temperature and altitude, any temperature limit, and the heat sources with the names you gave them. Our server uses these inputs only to compute the answer sent back to you, and are not stored, logged or shared. We have turned off request logging for the calculator. Cloudflare processes this request data as described under “This website”. Your session cookie is not passed to the part of the server that solves.

What stays in your browser

Your working project, the projects you save and your choice of units are stored in your browser’s local storage on your device. They are not sent to us, except as the inputs of a calculation as described above. Downloading or uploading a project file, the temperature map’s CSV and the printable report all happen in your browser. To delete saved projects, use Delete in the Projects menu or clear this site’s data in your browser.

Sharing

We do not sell or rent your data. We share it only with the service providers that process it to run this website: Cloudflare, which hosts it, and GitHub, for signing in.

Changes

If what we collect or how we use it changes, we will update this page and its effective date first.