Privacy Policy
Last updated: February 2026
Kakuso is operated by Adrian Sieradzki, Switzerland. We keep things simple: we collect the minimum data needed to run Kakuso, and nothing more.
1. What We Collect
We collect your email address for account creation and login. Your password is stored securely hashed — we never see your actual password. We store your study progress and preferences such as review schedules. If you sign in with Google, we receive your email address from your Google account.
2. How We Use Your Data
Your data is used solely to provide the Kakuso service: authenticating your account, saving your study progress, and managing your subscription. We do not sell, share, or use your data for advertising.
3. Third-Party Services
Stripe processes all payments. Your payment information goes directly to Stripe and is never stored on our servers. If you sign in with Google, we use Google OAuth and only receive your email address.
4. Cookies & Tracking
We use a single authentication cookie to keep you logged in. We also use your browser's local storage to save your preferences (such as theme and display settings) and to temporarily hold study results until they are synced with our servers. We do not use tracking cookies, analytics services, or advertising.
5. Data Security
Your data is transmitted over HTTPS. Passwords are securely hashed. We take reasonable measures to protect your information.
6. Your Rights
Your data is kept for as long as your account exists. You can access or delete your data at any time through the Settings page. Account deletion immediately and permanently removes all your information from our systems.
7. Changes
If we update this privacy policy, we will note the date of the last update on this page.
8. Contact
Questions about your privacy? Reach out at contact@kaku.so.