Terms of Service

1. Purpose and acceptance

These terms of service (the “Terms”) form the contract between you and the operator of the Chess X-Ray website (“we”, “us”). They apply to any visit to the site, to the creation of an account and to any analysis order.

By creating an account or placing an order, you confirm that you have read and accepted the Terms. If you do not agree with them, please do not use the service.

The Terms that apply to an order are those in force on the day the order is placed.

2. Operator and legal notice

The Chess X-Ray website is operated by:

• Operator: Kevin Antoine EI (French sole proprietorship, “entrepreneur individuel”), trading as Chess X-Ray
• Address: [TO COMPLETE: business or registered-office address]
• SIREN: 880 412 440
• SIRET: [TO COMPLETE: SIRET of the active establishment]
• VAT: VAT not applicable, article 293 B of the French General Tax Code
• Publication director: Kevin Antoine
• Contact: contact@chessxray.com

The site is hosted by Vercel Inc., 440 N Barranca Ave #4133, Covina, CA 91723, United States (https://vercel.com). The database is provided by Supabase Inc., 970 Toa Payoh North #07-04, Singapore 318992 (https://supabase.com), and hosted in a data centre in Paris, France.

3. Description of the service

Chess X-Ray downloads your public games from chess.com or from Lichess, depending on the account you give, across all time controls (bullet, blitz, rapid, classical and daily), through the public API of that platform, up to your 10,000 most recent games. From those games we produce personalized, interactive learning content, whose key positions are evaluated by the Stockfish chess engine.

Before any purchase, a free preview shows you, for the chess.com or Lichess account you entered, the number of games found and the openings you have played in at least 25 games, ranked from most to least played, with your score in each. An “opening” here means a family of openings played with a given colour (for example the Scandinavian Defence as Black).

The following content is offered:

• Essential: three opening masterclasses, covering the three openings you play most, among those played in at least 25 games;
• Full Repertoire: one masterclass for each opening you have played in at least 25 games, up to eight;
• Tactics add-on: lessons drawn from your own mistakes, built from a full Stockfish analysis of your most recent games: that analysis covers only part of your games, not all of those we download. Their number depends on your games: around 150 for a regular player;
• Full Repertoire with the Tactics add-on: both of the above, bought together;
• upgrade from Essential to Full Repertoire: the Full Repertoire masterclasses you do not own yet.

A masterclass presents an opening the way you play it: your usual moves, the deviations you keep repeating and what the engine recommends, as interactive chapters. The openings covered are those in the preview, in the same order. If you play new games between the preview and the analysis, the order may change slightly; the analysis is based on your games at the time it is carried out.

If your account has fewer openings played in at least 25 games than the number of masterclasses included in the plan, the preview tells you so before purchase, and you only receive the masterclasses for those openings.

The lessons of example players can be viewed freely, without an account, so that you can judge the result before ordering.

Lessons offered in a language other than French or English may have been written or translated with the help of automated tools.

4. Account and eligibility

To order an analysis, you need an account. You sign in with Google, with Twitch, or with a sign-in link sent by e-mail. We do not create or store any password.

You must be at least 15 years old to create an account on your own. If you are under 15, the account must be created with the consent of a parent or legal guardian. The service is in no case intended for children under 13. If you are a minor, any purchase must be authorized by a parent or legal guardian.

You are responsible for access to your account, and therefore for the security of the mailbox or of the Google or Twitch account you use to sign in. Tell us without delay if you believe someone else is using your account.

The information you give us must be accurate.

5. Chess.com and Lichess data, non-affiliation

Chess X-Ray is an independent website. It is not affiliated with, endorsed by or sponsored by Chess.com or Lichess. All names and trademarks mentioned belong to their respective owners.

We only read public data, available through the chess.com or Lichess public API: your games and the public information of your profile (whether the account exists and is open, ratings, number of games). We will never ask for your chess.com or Lichess password, and we do not access any private data in your account.

By giving us a chess.com or Lichess username, you declare that this account is your own. Ordering the analysis of another person’s account is not allowed. We do not analyse a Lichess account that is closed or marked by Lichess for a breach of its terms of service.

The service depends on the availability of the chess.com and Lichess public APIs, which we do not control. If either platform changes, restricts or closes that access, the service may be slowed down, modified or interrupted. If an analysis you have already paid for cannot be produced for that reason, it is refunded (see section 7).

6. Price, payment and delivery

Every purchase is paid once: it is not a subscription and nothing is charged again. On the date of these Terms, prices are as follows, including all taxes, in euros in the European Union and in US dollars elsewhere:

• Essential: €9.99 or $9.99;
• Full Repertoire: €19.99 or $19.99;
• Full Repertoire with the Tactics add-on: €24.99 or $24.99;
• Tactics add-on bought separately: €9.99 or $9.99;
• upgrade from Essential to Full Repertoire: €9.99 or $9.99.

VAT not applicable, article 293 B of the French General Tax Code. No tax is added to the price at payment.

The currency is chosen from the country inferred from your connection. If you live in the European Union and are offered a price in dollars, write to contact@chessxray.com before ordering: you can pay in euros. The payment is charged in the currency shown; if your card works in another currency, the conversion and any fees for it are applied by your bank, on its own terms.

The price and currency that apply are the ones shown on the payment page, before you confirm your order. The order is final only once the payment has been validated.

A promotion code, for example the one offered with a gifted course, applies on the terms announced with the offer (amount of the discount and, where relevant, end date or first order only). The discount is shown on the payment page before you confirm your order.

Launch offer: with the code REDDIT or FROMX, for a first order placed no later than 26 October 2026 at 11:59 pm (Paris time), prices are as follows, in euros or in dollars depending on the currency of your order:

• Essential: €7.99 or $7.99;
• Full Repertoire: €14.99 or $14.99;
• Full Repertoire with the Tactics add-on: €19.99 or $19.99.

This offer does not apply to the Tactics add-on bought separately, nor to the upgrade from Essential to Full Repertoire.

After a first purchase, you can buy from your account the Tactics add-on, or the upgrade from Essential to Full Repertoire, if you do not own them yet. Each of these purchases is a separate order, governed by these Terms as in force on the day of that purchase. A purchase only adds content: it never removes or replaces anything you already own.

Payment is handled by our payment processor, Stripe (Stripe Payments Europe, Limited, Dublin, Ireland). Your card details are entered directly with that processor: we do not receive or store them. A confirmation, restating the details of the order, is sent to you by e-mail after each purchase.

Analyses are processed in order of arrival. Delivery is therefore not instant, and may take longer when many requests are waiting. We commit to delivering the content of each purchase no later than 7 days after the payment for that purchase has been validated. You can follow the progress from your account.

For an add-on or an upgrade to Full Repertoire bought later, delivery means adding the newly purchased content to your account: the Tactics add-on lessons, or the masterclasses you were missing. A Tactics add-on bought later covers your most recent games as of the date of that purchase. Only the corresponding analysis step is carried out; the content you already own stays unchanged and available in the meantime. The 7-day period runs from the payment for that purchase.

Content is delivered in digital form, in your account on the site. Nothing is shipped on a physical medium.

7. Right of withdrawal and refunds

If you are a consumer, you have in principle 14 days from each purchase to withdraw, without giving any reason (article L221-18 of the French Consumer Code).

However, the content is supplied in digital form, without a physical medium, and produced specifically for you, from your own games. At every purchase, whether a plan, the Tactics add-on or the upgrade to Full Repertoire, a checkbox therefore asks, before payment, for your express consent for the analysis to begin before the end of the 14-day period, and for your acknowledgement that you thereby lose your right of withdrawal for that purchase. The purchase cannot be made without ticking that box. That consent and acknowledgement are kept with the order and restated in the confirmation sent by e-mail. In accordance with article L221-28 of the French Consumer Code, the right of withdrawal can no longer be exercised once the analysis has begun under those conditions.

As long as the analysis for a purchase has not begun, you can cancel that purchase and receive a full refund. Simply write to contact@chessxray.com, stating clearly that you wish to withdraw and giving the e-mail address of your account.

We also refund you if the purchased content cannot be produced, for example because the chess.com or Lichess account you gave has no usable games, because of a technical failure on our side, or if we are unable to deliver within the 7-day period set out in section 6. The refund covers the purchase concerned; if only part of the purchased content cannot be produced, it covers the corresponding share.

Refunds are made to the payment method used for the purchase, for the amount paid and in the same currency, no later than 14 days after your request or after we establish that the content cannot be produced.

8. Acceptable use and fair play

The service analyses finished games only. It is designed to help you improve between your games, never during them.

Using Chess X-Ray, Stockfish or any other chess engine during a game in progress violates the rules of chess.com and Lichess and is forbidden under these Terms.

You also must not:

• submit another person’s chess.com or Lichess username as if it were your own;
• resell, republish or publicly distribute the lessons and masterclasses beyond your personal use;
• scrape the site’s content, bypass its protections or disrupt its operation;
• use the service for unlawful purposes or to harm others.

9. Intellectual property

The site, its code, its design, its texts, and the lessons and masterclasses we produce belong to us or are licensed to us. They are protected by intellectual property law.

By ordering an analysis, you receive a personal, non-exclusive and non-transferable licence to view and use your lessons and masterclasses for your private, non-commercial use. This licence lasts as long as your account is open and the service is operated. If we were to shut the service down, we would give you reasonable notice.

Your games remain yours. They are public data made available by chess.com or Lichess: we claim no rights over them and use them only to produce your analysis.

Stockfish is free software distributed under the GNU General Public License version 3 (GPL v3). It belongs to its authors. Its source code is available at https://stockfishchess.org. Nothing in these Terms restricts the rights that licence grants you over Stockfish.

The chess pieces shown on the site and in GIFs are the work of Colin M. L. Burnett (the “cburnett” set), used under the free licences he published them under.

10. Warranties and liability

The lessons are educational. We do not guarantee any rating improvement or any sporting result: your progress depends above all on your own work.

The Stockfish engine’s evaluations are provided “as is”. A chess engine can be wrong or change its mind depending on search depth, and an explanation may contain a mistake. If you spot one, let us know and we will fix it.

We do our best to keep the site available, but cannot guarantee uninterrupted operation. We are not responsible for interruptions caused by third parties (chess.com, Lichess, hosting providers, internet access providers, the internet itself) or by force majeure.

If you are a consumer, you benefit from the statutory guarantee of conformity applicable to digital content and digital services (articles L224-25-12 and following of the French Consumer Code) and from the guarantee against hidden defects (articles 1641 to 1649 of the French Civil Code). Nothing in these Terms limits those guarantees or any right that the law mandatorily grants you.

If you use the service in a professional capacity, our liability is limited, to the fullest extent permitted by law, to the amount you paid for the order concerned.

11. Personal data

The data controller is the operator identified in section 2. We store the following data:

• your e-mail address;
• the name and avatar passed on by the sign-in provider you chose (Google or Twitch);
• your chess.com or Lichess username, and the public information of that account that we display (chess.com avatar, ratings);
• the language chosen for your lessons;
• your progress through the lessons;
• your analysis request and its status;
• the plans and add-ons purchased, any promotional code used and where it came from (for example Reddit or X), the date of each payment, your consent to the analysis starting immediately, and the customer identifier assigned by our payment processor (we never receive your card details).

This data is used to create your account, to produce and deliver your analysis, to track your progress and to answer your requests. Processing is based on the performance of our contract with you and, for the security and improvement of the service, on our legitimate interest. We do not sell your data.

Our providers have access to it only as far as their task requires: Vercel (site hosting), Supabase (database), Resend (sending e-mails, including sign-in links), Google and Twitch (sign-in, if you use them) and Stripe (payment) and DataFast (audience measurement). Some of them are established outside the European Union; any transfer is then covered by the safeguards required by the GDPR.

We may also write to you personally about your account or about a purchase you started and did not complete. You can object at any time, by replying to that message or by writing to contact@chessxray.com.

Your data is kept for as long as your account is open, then deleted, except for data the law requires us to keep (accounting records, for example).

Waitlist. When too many analyses are waiting, purchases are paused and you can join a waitlist. We then keep your account e-mail address, your chess.com or Lichess username, your language, the plan you were considering, and the dates on which you joined, were invited and, where applicable, purchased. This data is used only to let you know by e-mail, in order of sign-up, when you can order: never for any other mailing. It is deleted six months after you joined if you have not purchased, or as soon as you ask to leave the list by writing to contact@chessxray.com.

Cookies. The site sets four kinds of cookies:

• a sign-in cookie, required to keep you signed in to your account: it is only set when you sign in;
• a language-preference cookie, “xr-lang”, which remembers the language the site is shown to you in: that of the first page you visit, then the one you choose (lifetime: 1 year);
• a promotional-offer cookie, “xr_promo”, set only when you click on a promotional offer (for example the banner of a course offered via Reddit or X), to apply the corresponding code when you pay (lifetime: 30 days);
• a campaign cookie, “xr-utm”, set when you reach the site through a campaign link (for example from a post on Reddit or X): it holds only that campaign’s codes (source, medium, name), never your e-mail address or your username, and lets our audience measurement attribute your sign-up to that campaign when you open the sign-in link in another browser (duration: until you close your browser);
• two audience-measurement cookies from our provider DataFast: “datafast_visitor_id”, which recognises your browser from one visit to the next (lifetime: 1 year at most), and “datafast_session_id”, which groups the pages viewed during a single visit (lifetime: 30 minutes).

Audience measurement tells us which pages are viewed, where visitors come from (referring site, country inferred from the IP address, device and browser type) and which visits lead to a purchase. For that last point, the identifiers from the two DataFast cookies are attached to your payment at Stripe. We do not use them for advertising and do not share them with any other third party.

Usernames entered. When you enter a chess.com username on the site (home page or free preview), signed in or not, we keep that username, the day it was entered, the form used and, where relevant, the result of the preview (account found, without games, or not found). This information is linked neither to your account, nor to your IP address, nor to a cookie, nor to your visit; your IP address is used only, in memory and without being recorded, to limit the number of requests. It is used to prepare the preview faster and to measure, in aggregate figures, how many previews lead to an order. This processing is based on our legitimate interest. The information is deleted after one year: this period lets us also count orders placed several months after a first preview, and compare periods of the year. The holder of a chess.com account can have the lookups of their username deleted at any time by writing to contact@chessxray.com.

Gifted courses. During one-off campaigns, for example on Reddit’s r/chess forum or on X, we produce free of charge the course of players whose chess.com username is publicly given to us. Each campaign states, in the post that launches it, what is offered and, where relevant, how many places there are (for example the first 20 replies). A gifted course is not an order: no payment is made for it, and the delivery time in section 6 does not apply to it. That course is built solely from the public games of that account. It is published on a page that anyone with its link can open, which shows the chess.com username but is not indexed by search engines. The Reddit or X username of the person who made the request is kept to follow up the campaign and is not published. This processing is based on our legitimate interest in making the service known, in response to that public request. The holder of the chess.com account, as well as the person who made the request, may have the page taken down at any time by writing to contact@chessxray.com: we take it down within 7 days, and the associated username is deleted with it.

GIF tool. The GIF page runs in your browser: the game you paste (PGN) and the GIF it produces are not sent to us and are not kept. If you paste a chess.com or lichess game link, our server uses it to fetch the game and send it back to you, without keeping it; your IP address is only used, in memory and without being recorded, to limit the number of requests. The player names shown in the GIF come from the game you provide: if you share the GIF of a game played by others, you are responsible for that sharing.

You have the rights of access, rectification, erasure, restriction, objection and portability. To exercise them, write to contact@chessxray.com. You may also lodge a complaint with the French data protection authority, the CNIL (https://www.cnil.fr), or with the authority of your country of residence.

12. Suspension, termination and account deletion

You can ask for your account to be deleted at any time by writing to contact@chessxray.com. Deletion permanently removes access to your lessons and your progress, with no refund for analyses already delivered.

We may suspend or close an account in case of a serious or repeated breach of the Terms, in particular cheating, payment fraud or impersonation of a chess.com or Lichess account. Except in an emergency, we first warn you by e-mail so that you can explain.

If we close your account through no fault of yours, any analysis paid for and not yet delivered is refunded.

13. Changes to the terms

We may change the service and these Terms. The date of the last update is shown at the top of this page.

For any significant change, we notify you by e-mail or by a notice on the site before it takes effect. Orders already placed remain governed by the Terms in force on the day of the order.

14. Governing law and disputes

These Terms are governed by French law. If you are a consumer living in another European Union country, you keep the protection of the mandatory rules of your country of residence.

If something goes wrong, please write to us first: most problems are easily solved. If you are a consumer and your written complaint has not been resolved, you may use a consumer mediator free of charge (article L612-1 of the French Consumer Code): [TO COMPLETE: consumer mediator name and contact details].

The European Online Dispute Resolution (ODR) platform was closed on 20 July 2025. Consumers living in the European Union can turn to the European Consumer Centres Network (https://www.eccnet.eu) for a cross-border dispute.

Failing an amicable settlement, the dispute is brought before the French courts having jurisdiction under ordinary rules. If you are a consumer, you may also bring the case before the court of the place where you live.

15. Contact

For any question about the service, an order or these Terms: contact@chessxray.com.