Privacy

What we keep, and why

Last updated October 2026.

Without an account

You can use the whole site without signing in. Your practice history is saved in your own browser, not on our servers. When you submit a set, your answers are sent to our server to be graded and are not kept.

With an account

We keep only what the account needs:

• Your username and a secure password hash, to sign you in. We never store your password as plain text.
• A display name. It starts as your username, and you can change it once. It is shown on the leaderboards, next to your scores.
• Your answers, scores, XP, and streak, so your progress follows you between devices.

We don’t collect your real name, photo, school, location, or phone number, email address, or birth date when you create an account.

Who else is involved

• Our host, Railway, runs the site and its database.
• The page loads fonts from Google Fonts, and the math calculator from Desmos.

We don’t sell your data, show ads, or use tracking or analytics tools.

Cookies

Cookies keep you signed in and secure the sign-in process.

Your choices

On your account page you can download everything we hold about you, choose your display name, or delete your account. Deleting removes your account and all of its data straight away.