Privacy Policy

Effective 19 September 2026. Last updated 19 September 2026.

PrepStar is an SAT and ACT preparation service operated by Moose ML Inc. This policy explains what personal information we collect, why we collect it, who we share it with, and the choices you have. It applies to prepstar.ai, app.prepstar.ai and any related service we provide.

Students are often minors. We collect as little as the service needs, we never sell personal information, and we never use a student's work to train a general-purpose AI model.

1. Who we are

Moose ML Inc. is the controller of the personal information described in this policy. You can reach us at support@prepstar.ai for any privacy question, including a request to access or delete your data.

2. Information we collect

Information you give us

Account details. Your email address and display name. If you sign in with Google, we receive your email address, name and profile picture from Google. We never receive your Google password.
Study profile. Target score, intended test date, and the goals you set.
Your work. Answers to practice questions, full-length practice tests, flashcard reviews, and messages you send to the AI tutor.
Uploads. Photographs or PDFs of paper practice tests that you submit for grading.
Household links. If a parent or guardian is linked to a student account, we record that relationship so we can send progress summaries.
Payment details. Subscriptions are processed by Stripe. Stripe receives your card details directly; we receive only the subscription status and the last four digits.

Information we collect automatically

Usage data. Which lessons and questions you opened, how long you studied, and when.
Technical data. IP address, browser and device type, and timestamps, recorded in server logs for security and troubleshooting.
Cookies. We use a small number of strictly necessary cookies to keep you signed in and to protect against forgery. We do not use advertising cookies and we do not track you across other websites.

3. How we use information

To provide the service: showing lessons, grading answers, scoring practice tests and generating explanations.
To personalise study: identifying the skills you miss most and generating practice that targets them.
To predict scores and show progress to you and, where linked, to your parent or guardian.
To send transactional email: sign-in codes, account notices, progress summaries and reminders you have opted into.
To take payment and manage subscriptions.
To keep the service secure, prevent abuse, and meet our legal obligations.
To improve the product in aggregate, using statistics that do not identify any individual.

4. Artificial intelligence

PrepStar uses large language models to grade free-response answers, explain questions, generate new practice items and power the tutor. These models run on Amazon Bedrock inside our own AWS account.

Your answers and tutor conversations are sent to the model only to produce your result.
Your content is not used to train foundation models, either by us or by our model provider.
Model output is checked against an expected structure before it is stored or shown to you.
AI output can be wrong. It is study guidance, not a guarantee of any score or outcome.

5. How we share information

We do not sell personal information and we do not share it for advertising. We share it only with service providers who process it on our instructions:

Provider	Purpose
Amazon Web Services	Hosting, database, file storage, email delivery and AI inference. Data is stored in the United States.
Google	Sign in with Google, if you choose it.
Stripe	Payment processing and subscription billing.

We may also disclose information if required by law, to enforce our terms, or to protect the rights and safety of our users. If Moose ML Inc. is involved in a merger or acquisition, personal information may transfer to the acquirer under this same policy.

6. Children and students

PrepStar is intended for students aged 13 and over. We do not knowingly collect personal information from children under 13. If we learn that we have, we delete it promptly. If you believe a child under 13 has given us information, write to support@prepstar.ai.

If you are under 18, you must have your parent or guardian's permission to use PrepStar. A parent or guardian linked to a student account can see that student's progress summaries, request a copy of their data, and ask us to delete the account.

7. How long we keep information

Account and study data is kept while your account is open.
When you delete your account we remove your profile, your answers, your tutor conversations and your uploaded files.
We keep de-identified records of AI usage, with no user identifier attached, so we can account for costs.
Server logs are kept for a limited period for security and then discarded.
We keep billing records for as long as tax and accounting law requires.

8. Security

Data is encrypted in transit and at rest. Access to production systems is limited to people who need it, using single sign-on with multi-factor authentication and short-lived credentials. We do not store passwords ourselves; authentication is handled by Amazon Cognito. No system is perfectly secure, but we take these obligations seriously, particularly because many of our users are minors.

9. Your rights and choices

Access and portability. Ask us for a copy of the personal information we hold about you.
Correction. Update your profile in the app, or ask us.
Deletion. Delete your account from settings, or ask us to do it.
Email preferences. Turn off progress summaries and reminders in settings or by using the unsubscribe link. We will still send essential account email such as sign-in codes.

Depending on where you live, you may have further rights, including the rights California residents have under the CCPA to know what we collect, to delete it, and not to be discriminated against for exercising those rights. We do not sell or share personal information as those terms are defined under California law. To exercise any right, write to support@prepstar.ai. We will not charge you and we will respond within the time the law allows.

10. International users

PrepStar is operated from the United States and all data is processed there. If you use the service from outside the United States, you understand that your information will be transferred to and processed in the United States, where privacy law may differ from that of your own country.

11. Changes to this policy

We will update this page when our practices change, and we will change the "last updated" date above. If a change materially affects how we use your personal information, we will tell you by email or in the app before it takes effect.

12. Contact us

Moose ML Inc.
Email: support@prepstar.ai