Privacy policy
Last updated September 2, 2026
The short version: I collect what I need to run your account and take your payment. I don’t sell it.
What I collect
- Your email, a password (Clerk handles it, I never see it), and your name if you give one.
- Payment info through Stripe: your email, a Stripe customer and session ID, and the date. Your card never touches CalcGrind.
- Your studying: questions answered, missed, and bookmarked, so your progress follows you across devices.
- Standard server logs (IP, browser, pages, time), kept briefly for debugging.
What I don’t do
No ads, no third-party ad or cross-site trackers, and I never sell or share your data.
Cookies
One cookie, from Clerk, so you stay signed in. Your theme choice is saved locally on your device. Neither tracks you, so there’s no banner.
Who else touches your data
The services that run the site, each doing one job and getting only what it needs:
- Clerk, for accounts and sign-in.
- Stripe, for payments.
- Neon, the database.
- Vercel, the host.
- Resend, the purchase email.
Only about your purchase or account. No newsletters, no marketing.
Kids
You must be 13 or older to sign up. I don’t knowingly collect anything from anyone younger; parents can email me to remove an under-13 account.
Your data, your call
Email me from your account address to see or delete your data, usually the same day. Deleting removes your study history for good. Purchase records stay a few years for tax rules, and Stripe keeps its own copy.
Keeping it safe
HTTPS throughout. Clerk hashes passwords (I never store them), and card details never reach my servers. If anything ever goes wrong with your data, I’ll tell you.
Changes
If this changes, I’ll update the date above, and email you if it matters.