Privacy

DuctStudy · updated October 1, 2026

DuctStudy is a free study site for duct cleaning technicians. This page says what it keeps, where, and what leaves your device.

Without an account

Everything works signed out. Your progress is kept in your browser, on your device, and is not sent to us. Your device also keeps a copy of the app so it opens with no signal, and today's date, used for the daily count described below.

If you sign in

• With Google: we get your Google account ID, name and email address. We ask Google for nothing else, and we never see your password.
• With an emailed code: we keep your email address, from the moment you ask for a code. The 6-digit code is kept only in scrambled form and stops working after ten minutes.
• Your browser keeps a sign-in key, so you stay signed in on that device until you sign out.
• Your study progress is saved to your account so it follows you to another device: which questions you answered and how, lessons, recall cards, test scores, job call results, simulator scores, your exam date if you set one, and when you were last here.

Answers that go to an AI model

Three things, all optional and only when you are signed in, send text or sound to another company's model to do their job:

• Ask why, the tutor under a drill answer: the practice question, its answer and reasons, the choice you picked, and what you type go to Anthropic. We do not keep the conversation.
• The microphone in the tutor box: your recording goes to OpenAI to be turned into text. We do not keep the recording.
• Graded job calls: the answer you write, with the job call and its key, goes to Anthropic. The grade is saved with your progress.

Those companies handle what they receive under their own terms. We count how many of these calls each account makes in a day, to hold a daily limit.

Problem reports

When you send Report a problem, we get your note, the screen you were on, the question ID, the app version and your browser type. If you are signed in, your account name goes with it; if not, it is sent as a guest. A report sent while your saved progress could not be read also carries the start of that saved progress.

Usage counts

The site counts how often its parts are used (drills started, tests finished, lessons read, devices active that day) as plain daily totals. Those totals carry no name, account, device ID or answers.

Limits against abuse

To cap sign-in emails and problem reports, we keep daily counters tied to a scrambled form of the internet address, or the email address, that asked. We do not store your internet address itself.

Other companies involved

• Cloudflare runs the site and its database, and sends the sign-in emails.
• The page loads its fonts from Google Fonts, so your browser asks Google for those files.
• Google, Anthropic and OpenAI, as described above.

Company accounts

If your account belongs to a company, that company's owner can see your name, progress and test scores on its dashboard. The older DuctStudy app at /ascs-en signs in with an access code from a company and keeps the name typed with it.

What we don't do

We don't sell or share your information, show ads, or use tracking cookies. The only cookie is one that lasts ten minutes while you sign in with Google.

Deleting it

Email bennyforeman1@gmail.com from the address you signed in with and we will delete your account and its progress. Progress in your own browser can be cleared any time: Me, then Backup, restore, and reset, or clear this site's data in your browser.

Contact

bennyforeman1@gmail.com

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