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: Chess X-Ray
• VAT: VAT not applicable, article 293 B of the French General Tax Code
• Publication director: Chess X-Ray
• 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).

Top 10 offered as a preview. After you create your account, if you have not yet bought the Top 10, we may compute it from your games and send it to you by e-mail: the first 3 mistakes are free to open, the others after you buy the Top 10, at the price in section 6. This preview is not an order and does not commit you to any purchase. If you then buy the Top 10, on its own or included in a plan, it is completed from your games as of the date of that purchase.

The following content is offered:

• “Your 10 costliest opening mistakes” (the “Top 10”): a short course on the opening mistakes you repeat most, up to ten. A mistake is an opening position where you keep playing the same move although it costs you winning chances. Each one has its own interactive chapter: the position to replay, how many times you played that move there, what it costs you, why it is a mistake and the right continuation. They are looked for in your most recent games, in the time controls and period chosen in the preview. If your games contain fewer than ten, you receive the ones we find, and the price is refunded pro rata for the missing ones, on simple request;
• Essential: three opening masterclasses, covering the three openings you play most, among those played in at least 25 games, and the Top 10;
• Full Repertoire: one masterclass for each opening you have played in at least 25 games, up to eight, and the Top 10;
• 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;
• 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

Weekly video subscription. The subscription gives you, every Sunday, a video of about 3 minutes made from your own recent games, and access to all your past videos in your account. A first free video, with no payment card, may be offered to you; not every account is offered one. On the date of these Terms, the subscription costs €4.99 per month or €39.99 per year, all taxes included. The price that applies is the one shown on the payment page before you confirm.

First month free. The first monthly subscription of an account starts with a free month of 30 days. Your payment card is asked for at the start, but nothing is charged during those 30 days; the first charge of €4.99 happens at the end of the free month, then the subscription carries on under the terms below. The free month is given only once per account and only on the monthly subscription: the yearly subscription has none. We do not send a reminder before the free month ends. If you cancel during the free month, nothing is charged and the subscription ends at once, together with the making of new videos; the videos already received stay in your account.

The subscription renews automatically at the end of each period (one month or one year) for a period of the same length, and is charged at the start of each new period, until you cancel it. You can cancel at any time, in one click, from your account (“Manage subscription”) or from the link in each Sunday e-mail. After the free month, cancellation takes effect at the end of the period already paid: you keep your videos and receive the remaining ones until that date, and nothing more is charged afterwards. A period that has started is not refunded pro rata, except under section 7.

For a yearly subscription, we send you an e-mail between one and three months before the renewal date, reminding you of that date, of the price and of how to cancel (article L215-1 of the French Consumer Code).

If a payment fails, Stripe tries again for a few days. Without a successful payment, the subscription ends and no new video is made; the videos already made stay in your account.

Purchases of courses (Top 10, Essential, Full Repertoire and their add-ons). Each of these purchases is paid once: it is not a subscription and nothing is charged again. They are no longer sold since the launch of the subscription, and those already bought stay governed by the terms below, which keep applying to them. On the date of these Terms, their prices were as follows, including all taxes, in euros in the European Union and in US dollars elsewhere:

• Your 10 costliest opening mistakes (Top 10): €4.99 or $4.99;
• Essential, Top 10 included: €9.99 or $9.99;
• Full Repertoire, Top 10 included: €14.99 or $14.99;
• Tactics add-on bought separately: €9.99 or $9.99;
• upgrade from Essential to Full Repertoire: €4.99 or $4.99.

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, Top 10 included: €7.99 or $7.99;
• Full Repertoire, Top 10 included: €9.99 or $9.99.

This offer does not apply to the Top 10, the Tactics add-on bought separately, or the upgrade from Essential to Full Repertoire. It is valid for a first order: if you buy the Top 10 first, it no longer applies to a later order.

If you already own the Top 10 bought on its own, the price of Essential or Full Repertoire stays the same: the price already paid for the Top 10 is not deducted from it, and you keep the Top 10 you already have.

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. The Top 10, whether bought on its own or included in Essential or Full Repertoire, is delivered no later than 24 hours after the payment has been validated; if it is not delivered within that time, the share corresponding to the Top 10 is refunded on simple request, and it is still delivered to you. The value of that share is the price of the Top 10 bought on its own on the date of your purchase; it is also the value used for the pro rata refund set out in section 3. 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 can withdraw from each purchase, whether a plan, the Top 10, the Tactics add-on or the upgrade to Full Repertoire, within 14 days from the day of that purchase, without giving any reason, even if the content has already been delivered to you (articles L221-18 et seq. of the French Consumer Code).

To exercise this right, send us, before that period ends, a clear statement of your decision to withdraw, for example by e-mail to contact@chessxray.com, giving the e-mail address of your account. You may also, without being required to, use the following model:

“To Chess X-Ray, contact@chessxray.com: I hereby give notice that I withdraw from the contract for the following purchase: [plan purchased], ordered on [date], account e-mail address: [e-mail]. Name: [name]. Date: [date].”

We refund all sums paid for that purchase no later than 14 days after receiving your request, to the payment method used, at no cost to you. Access to the content of that purchase is then removed from 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.

Subscription: if you are a consumer, you can withdraw from your subscription within 14 days from the day you subscribed, without giving any reason, even if videos have already been delivered to you, in the same way as above. We then refund in full the first payment and the subscription ends at once. After those 14 days, you can cancel at any time, under section 6, with effect at the end of the period already paid.

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, except through the sharing link provided for the Top 10 (section 11);
• 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. We use them to produce your analysis and, on the terms of section 11, to illustrate our communication.

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, 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). 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 about your account, about a purchase you started and did not complete, or about Chess X-Ray news close to what you use. Each of these e-mails contains an unsubscribe link: one click is enough, without signing in, and you no longer receive any reminder or news. You can also object by writing to contact@chessxray.com. E-mails about a paid order (confirmation, delivery, refund) are sent to you in any case, as they are part of the service you bought.

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 the following 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);
• a cookie giving access to the offered Top 10, “xr_gift”, set only when you open the link in the offered Top 10 e-mail: it lets that Top 10 be shown without signing in and is only sent on that Top 10’s page (lifetime: 90 days);
• two cookies for our own audience measurement: “xr_vid”, a randomly drawn identifier that recognises your browser from one visit to the next (lifetime: 1 year), and “xr_sid”, which groups the pages viewed during a single visit (lifetime: 30 minutes, extended at each page); only our server can read them.

Audience measurement tells us which pages are viewed, where visitors come from (referring site, campaign, country inferred from the IP address, device type, browser and operating system), what is done on them (for example a click on an offer, or on a link to another site, of which we keep only the site’s name) and which visits lead to a purchase. For that last point, the “xr_vid” cookie’s identifier is attached to your payment at Stripe, and the amount paid is recorded with your visit. We run it ourselves: for each page viewed or action, we keep the “xr_vid” cookie’s identifier, the visit’s identifier, the page address without its parameters, where the visit came from and the information above, but never your IP address, the full description of your browser, your e-mail address or your account. This information is deleted after 13 months. If you create an account, your browsing measured in this way is also linked to that account, on the terms of the “Tracking your interest in our offers” paragraph. We do not use it for advertising and do not share it with any 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.

Public requests and gifted courses. During one-off campaigns, for example on Reddit or on X, a person may publicly give us, in a comment, a chess.com or Lichess username to have it analysed. Depending on what the campaign announces, we reply publicly to that comment with a few playing habits drawn from that account’s public games, or we produce masterclasses or a full course free of charge. 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. It is built solely from the account’s public games and published on a page that anyone with its link can open, which shows the username but is not indexed by search engines. To follow up these requests, we keep the username of the person who made the request, the link to and the text of their public comment, and the community where it was posted, the chess.com or Lichess username given, what we offered, the text of our reply and the status of the request. This information is not published, except our reply, visible under the comment. It is deleted 12 months after the request, or as soon as we notice that its author has deleted their comment. This processing is based on our legitimate interest in making the service known, in response to a public request. The holder of the chess.com or Lichess account, as well as the person who made the request, may have our reply and the course page taken down at any time by writing to contact@chessxray.com: we take them down within 7 days, and the associated information is deleted with them.

Games used in our communication. We may use positions and moves taken from the public games analysed on Chess X-Ray, including yours, to illustrate our posts on social media and on the site (for example a position, a typical mistake or an exercise, as an image, a GIF or a video). These posts mention neither your username, nor your name, nor the fact that you are a customer, unless you agree to it or you are a public player as described in the “Public players” paragraph below. This processing is based on our legitimate interest in making the service known, using games that are already public. You can object at any time by writing to contact@chessxray.com: we stop using your games, and within 7 days we remove the posts drawn from them that you point out to us.

Offered Top 10. To offer you the Top 10 as a preview (section 3), we keep with your account your chess.com or Lichess username, the result of the computation (the mistakes found and the date of the games taken into account), a secret link specific to your account, and the dates the e-mail was sent and the link first opened. That link opens your Top 10 page without signing in, and nothing else of your account: anyone you pass it on to can see that page. This processing is based on our legitimate interest in presenting our service to people who have created an account. This information is deleted with your account. Each e-mail contains a one-click unsubscribe link, and you may object to this processing at any time by writing to contact@chessxray.com.

Sharing the Top 10. You can create a link to show your Top 10 to whomever you like. The shared page shows only the content of that course (positions, moves, explanations, exercises), with no link to your games or to your other courses, and is not indexed by search engines. It shows your chess.com or Lichess username only if you choose so when sharing. You can remove the link at any time from your account: it stops working at once, and sharing again creates a new link. We keep the link, its creation date and your choice to show your username or not, for as long as the sharing is active; everything is deleted with your account. Anyone who receives the link can see the page: share it knowingly.

Public players. We may also comment, under their name, on the public games of players known to the public, such as titled players, streamers and chess personalities, for example in a sample page or a post presenting their opening habits according to the Stockfish engine. This is an independent analysis: these players have no connection with Chess X-Ray and do not endorse it, and we use neither their image nor their name to suggest otherwise. This processing is based on our legitimate interest and on the freedom to comment on public games. The player concerned can object at any time by writing to contact@chessxray.com: within 7 days we remove the page or posts concerned.

Tracking your interest in our offers. To know which accounts are interested in which offers and to tailor our exchanges, we link to your account your journey on the site (pages viewed, offers clicked, visits to the payment page), once signed in but also before you created your account, as recorded by our audience measurement through its “xr_vid” cookie (or, before, by the DataFast tool through its “datafast_visitor_id” cookie), including for accounts created before this version, and where your visit came from (for example a campaign or a post on Reddit), as well as, where relevant, the public request you made to us in a community such as Reddit and the username used for that request. When that link cannot be made directly through the cookie, we infer it from the match between the time you signed up and the time of a visit: such a match is uncertain, it is marked as such and may, by mistake, concern another person’s visit. Of that journey we keep only the pages, the actions, their dates and where the visit came from, with no IP address and no description of your device. From these we compute every night an interest score from 0 to 100, visible only to our team. This score triggers no automated decision: it changes neither your prices, nor your access to the service, nor the messages you receive. This processing is based on our legitimate interest in understanding the interest shown in our offers. This information is kept for 13 months at most, then deleted, and it goes with your account. You can object at any time by writing to contact@chessxray.com: your account is then excluded from this tracking, and the information already linked to it, including the link with your browsing, is deleted.

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.

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.