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Privacy Policy

Last updated: Oct 18, 2026

Who we are

ChessDrills is operated by Artem Karpov (Brazil). To reach us, use the contact page or write to contact@chessdrills.com.

What we collect

  • Public chess games. The free report reads the public games of the Chess.com or Lichess username you type in. You do not need an account. We read what those platforms already publish; we do not ask for your password or a login to either site.
  • Guest record. When you use features that remember your progress, we create a guest record on our server. It is tied to a random token stored in your browser and holds your training positions, your review progress, the Chess.com or Lichess username your training was built from and the time zone your browser reports. It holds no name and no email unless you add one.
  • Email address (optional). You can give us an email address to keep your progress and sign in on another device. An address typed into the email form is stored on your guest record while it waits to be confirmed, and we email you a link to confirm it. Nothing requires one.
  • Google sign-in (optional). If you sign in with Google, Google sends us your account's name, email address and profile picture. We keep only your Google account ID and email address, to recognise you next time. We do not store your name or picture.
  • Sign-in link data. When an email is requested for an address, we store a keyed hash of the IP address that asked and keyed hashes of the address (and of its mailbox, without any "+tag") in a short-lived count, so one address cannot be sent endless emails. We do not keep the IP address itself in these records. The sign-in link record holds the email address until it is deleted, a day after the link expires.
  • Card feedback. If you rate a training card or tell us what is wrong with it, we store your vote, your note and the position, and we delete them after 180 days.
  • Messages you send us. If you email us, we keep your address and your message so we can reply.
  • Usage data. Which pages you open and which features you use, collected by the analytics tools below, plus the technical data any web request carries, such as IP address and browser type.

How we use it

  • To build your report and show you which openings you score best and worst in.
  • To remember your progress between visits, and on another device if you add an email or sign in with Google.
  • To email you the confirmation and sign-in links you ask for.
  • To reply when you contact us.
  • To understand how the site is used and to fix problems.
  • To keep the service secure and to meet legal obligations.

Reports and share cards

A report and its share card are built from the public games of the username in the page address. A share card has a public link, so anyone who has the link can open it. If you would like a report or card about your username removed, ask us on the contact page.

Emails we send

If you add an email address, we send you the links you ask for: one that confirms the address and signs you in, and a sign-in link whenever you request one for another device. These links work once and expire after 24 hours. We may also offer a daily email that reminds you to review your positions. It would be sent only if the feature is available and you have given an address and chosen to receive it, at most once a day, and every message would carry a one-click unsubscribe link that stops it. Emails are sent through Resend.

Analytics and cookies

  • DataFast. We use DataFast to measure visits and product use. It sets first-party cookies on chessdrills.com: a visitor ID, kept for up to a year, and a session ID, so it can tell returning visitors and sessions apart. Player usernames are masked in the events we send to it, so DataFast does not receive the usernames you analyse.
  • Vercel Analytics. We use Vercel Analytics to measure page views and site performance.
  • Browser storage. Your browser remembers the last username you looked up, so forms can fill it in for you. If you use features that remember your progress, it also stores the token that identifies your guest record. This stays in your browser; clearing your browser data removes both and detaches you from the record.

You can block analytics and clear stored data in your browser settings.

Who processes data for us

  • Chess.com and Lichess. We call their public APIs to read public games. Their own privacy policies govern what they do with requests and data.
  • Vercel. Hosts the website and provides Vercel Analytics.
  • Hetzner. Hosts our servers and database, including guest records and email addresses.
  • Resend. Delivers our emails; it receives the address and the message.
  • DataFast. Provides product analytics, with usernames masked.
  • Google. Provides "Continue with Google". The button loads from Google on sign-in and email forms, so Google receives your IP address and browser details when it appears. If you use it, Google confirms the account you choose. Its own privacy policy governs what it does with that data.
  • Google Fonts. The site loads its typeface from Google Fonts, so Google receives your IP address and browser details when a page loads.

We do not sell your data and we do not share it for advertising.

How long we keep it

  • Guest records are deleted after 30 days without a review or an email request. Once you confirm your email address or sign in with Google, your record is kept until you ask us to delete it.
  • Sign-in links expire after 24 hours and are deleted a day after that, together with the keyed IP hash stored with them. The count of emails sent to an address is deleted after a day.
  • Card feedback is deleted after 180 days.
  • Emails you send us are kept as long as we need them to deal with your request.
  • Analytics data is kept by DataFast and Vercel under their own retention settings.

Deleting your data and your other rights

You can ask us at any time to delete personal data we hold about you, to send you a copy of it, or to correct it. Write to contact@chessdrills.com, say what you want and tell us the email address you used, or describe the browser you used if you added none. We act on these requests within a reasonable time. Depending on where you live, the law may give you further rights over your personal data, and we respect them.

Security

Guest records and email addresses are stored on our servers at Hetzner. We take reasonable measures to protect the data we hold, but no system on the internet is perfectly secure.

Children

ChessDrills is not directed at children under 13, and we do not knowingly collect their personal data, including email addresses. If you believe a child has given us some, tell us and we will delete it.

Changes to this policy

We will update this page when our practices change and revise the “Last updated” date above. If we start using data in a materially different way, we will say so on the site before it takes effect.

Contact

Questions about this policy: contact@chessdrills.com or the contact page.