Privacy & Policy

The short version

Practice works without an account. Accounts are for players aged 16 and older. We do not sell personal data, use it for advertising, or offer cash prizes. We collect limited, aggregate traffic and performance data to help keep the service available.

What other players can see

Signed-in players can see your nickname, rating, chosen country or region, and results in matches and leaderboards. World Records also shows your fastest perfect solves by graph type in Practice and Duels, including when your profile is private. Country display is optional. New accounts have detailed profiles and history public by default and can be made private through profile settings. Private profiles still show a player card, rank, rating, and basic competitive stats. Opponents can see the equations and scores disclosed by the game.

Shared links may contain equations or invite codes. Anyone you give a link to can potentially read or forward it. Use a nickname and avoid putting personal information in equations.

Traffic and performance measurement

Vercel Analytics and Speed Insights run by default on a small set of public game pages. They provide aggregate traffic and performance data so we can monitor demand, plan capacity, and maintain reliable service.

We limit measurements to known routes and strip query strings and fragments before sending them. We do not use advertising trackers, session replay, or custom analytics events.

Providers and sharing

Google provides sign-in; Vercel hosts the application and supplies traffic and performance measurement; Neon stores the production application database. They receive the data needed for their respective roles. Local development may use a database on the developer’s computer.

We may disclose information when legally required or necessary to investigate abuse, protect users, or respond to a security incident. We do not sell personal data or share it for cross-context behavioral advertising.

Providers may process information outside your country. Storage locations, provider contracts, international-transfer arrangements, and any required local representation must be assessed for the markets we serve; this notice does not assert EU-only hosting or certify that every transfer requirement is resolved. You can request information about applicable arrangements by contacting us.

Retention

Account identity, agreement records, rating, personal bests, and accumulated progress remain while your account is active unless you request removal. The application maintenance job removes daily and finished-match detail older than approximately one year, and anonymous daily detail older than the current day plus two previous days. Expired sessions, rate-limit records, and stale queues are also cleared by maintenance.

Cleanup occurs when the maintenance job runs. Provider logs, email, and backups have separate retention and may outlast removal from the live database. We do not claim that the application deletion button immediately removes every provider copy. Contact us for a request involving those systems. Cached views or copies held by other players may also persist briefly or independently.

Your choices and rights

Use the controls on this page to download account data, delete your account, or clear this browser’s game data. Country and profile-sharing choices are in profile settings. Account export excludes security secrets and other players’ identifying data.

Deleting an account removes its identifying details, submissions, sessions, rating, progression, and daily records from the live application database. Shared match scores may remain with a deleted-player placeholder to preserve opponents’ results. Clearing browser data signs out this device and removes its linked anonymous daily data; it does not delete an account or data held on another device.

Depending on applicable law, you may have rights to access, correction, deletion, restriction, objection, portability, and withdrawal of consent. Email us if the controls do not cover your request, including a parent’s request about a child. We may need proportionate identity verification. We will explain applicable legal exceptions or limits and respond within applicable deadlines. You may complain to your local data-protection authority where that right applies. Exercising a privacy right will not incur a fee for ordinary requests or change the price of the free game.

Children

Accounts are limited to age 16 and older. A parent’s agreement to game terms does not open an account for a younger child. Practice remains available without an account and uses the same limited operational measurement described above.

If we learn that an account belongs to a younger child, we will restrict it and review and remove improperly collected data as required. A parent or guardian can contact us to request review or removal. The game’s educational subject matter and stated age rule do not remove child-privacy obligations applicable to its actual audience.

Updates

The version above identifies this notice. We will explain material changes and obtain fresh consent when required. The cookies and storage section describes device storage in more detail.