Every move checked by Stockfish. No daily cap, no paywall.
Brilliant
Best move
Mistake
BlunderChester is your coach, on hand throughout puzzles, lessons, and games with hints, a second opinion, and the occasional word of encouragement. Not a chatbot bolted on top; Chester's read your actual pattern report.
These Terms govern your use of Chester at coachchester.com and in our iOS and Android apps. By creating an account or using Chester, you agree to them and to our Privacy Policy. Nothing in these Terms affects your statutory rights as a consumer.
Chester is run by Thomas Coase and James Kennedy, trading as Chester, in Ireland ("we", "us"). Email thomas.coase@gmail.com or jpk031004@gmail.com. Our postal address is available on request.
You must be 13 or older. If you're under 18, a parent or guardian must agree to these Terms for you, and paid plans must be bought by an adult. Give accurate details, keep your password private, and have only one account. You're responsible for what happens on your account. Only link a Chess.com or Lichess username you play on yourself. We may change names that are offensive, misleading or impersonate someone.
Chester analyses your public Chess.com or Lichess games and gives you puzzles, lessons, bot games, training plans and coaching. It needs an internet connection and works in current web browsers and our apps. Features change over time. If we significantly reduce a paid feature you've paid for, you can cancel and get a refund for the unused time. Chester isn't affiliated with Chess.com, Lichess or any other company named in it.
Coaching reports, training plan text and Ask Chester answers are generated by AI (Claude, by Anthropic). Text labelled "Chester" is AI-generated. Engine evaluations, AI answers and rating forecasts can be wrong. They're study aids, not advice. Automated filters keep Ask Chester to chess and block unsafe content.
If you're a consumer in the EU, EEA or UK, you can withdraw from a plan bought on our website within 14 days of buying it, without giving a reason, by using "Withdraw from contract here" on the Your Plan page or by emailing us from the email address on your Chester account. You can use the form below, but you don't have to. We'll refund you through Link within 14 days, minus a proportionate amount for any days of paid features you asked to start during that time. This applies when you first buy a plan or change plans, not to renewals. Purchases in our apps are handled by Apple or Google.
You must not:
You own what you type into Chester. You let us store and process it, including through our service providers, only to provide Chester to you. We may remove content that breaks these Terms.
To report illegal content or misuse, email us. If we restrict your account or content, we'll tell you why, and you can ask us to review the decision. Our email addresses are our point of contact under the EU Digital Services Act, in English.
You can delete your account at any time in Settings. This cancels a website plan immediately; cancel app plans in the App Store or Google Play. We may suspend or close an account that seriously or repeatedly breaks these Terms, or where the law requires it. We'll give reasons and, where reasonable, a warning first. If we close your account when you haven't broken these Terms, or close Chester or a paid plan (with 30 days' notice), we'll refund any unused paid time.
Chester and its content belong to us or our licensors. You may use it for your own non-commercial chess study. Third-party material, such as Stockfish, the Lichess puzzle database and the piece sets, is under its own licences, which are listed in the app.
We're responsible for foreseeable loss caused by our breach of these Terms or our failure to use reasonable care and skill. We're not responsible for unforeseeable loss, business losses, or services we don't control. Nothing in these Terms limits liability for death or personal injury caused by negligence, for fraud, or for anything else that can't be limited by law. Under Irish and EU law, Chester must be as described and fit for purpose, and you have the right to a remedy if it isn't. Apart from that, our total liability to you in any 12 months is limited to the amount you paid us in that time or €100, whichever is higher.
We'll give you at least 30 days' notice of significant changes to these Terms, and you can cancel before they apply. We may transfer these Terms to a company set up to run Chester, or to an organisation that takes it over, as long as your rights aren't reduced.
If you downloaded Chester from the App Store, Apple's standard Licensed Application End User License Agreement also applies, and Apple isn't responsible for the app or its support. If you downloaded it from Google Play, Google Play's terms also apply.
Irish law applies to these Terms. If you're a consumer, you also keep the protection of the mandatory laws of the country where you live, and you can bring proceedings in the courts there or in Ireland. If any part of these Terms can't be enforced, the rest still applies. If you have a problem, please contact us first.
This policy explains how Chester, our website and our apps, uses your personal data under the GDPR and Ireland's Data Protection Acts, and the UK GDPR for UK users.
The data controller is Thomas Coase and James Kennedy, trading as Chester, in Ireland. Email thomas.coase@gmail.com or jpk031004@gmail.com. Our postal address is available on request.
Other members who enter your account email in Compare see your name and overall stats. We may also use data to comply with the law or to establish, exercise or defend legal claims. You must give your account details and a chess username to use Chester.
Chester analyses your games automatically to choose what you should practise. This is profiling, but it doesn't make decisions with legal or similarly significant effects on you. Text labelled "Chester" is generated by AI.
We use one strictly necessary cookie, "session_token", to keep you signed in. It lasts 30 days if you choose "Keep me signed in", and otherwise until you close your browser. Display preferences are saved in your browser's local storage and are never sent to us. We use no analytics or advertising cookies or trackers. The news images in Professional Play load from Lichess's servers, which see your IP address.
Our service providers process data on our behalf under data processing agreements: Supabase (database, EU), Railway (servers, EU), Anthropic (AI) and Resend (email). Stripe's Link service (website payments), Apple and Google (apps), and Chess.com and Lichess (which receive usernames so we can fetch public games) handle data under their own privacy policies. We may also share data with authorities or advisers where the law requires it, or with a company or organisation that takes over Chester. We never sell your data or use it for advertising.
Anthropic, Resend and Stripe may process data in the US. That data is protected by the EU-US Data Privacy Framework or by the European Commission's Standard Contractual Clauses. We can give you details on request.
You can access, correct, delete, restrict, object to and port your data, and withdraw consent at any time. Use Settings, or email us, and we'll reply within one month. You can complain to Ireland's Data Protection Commission (dataprotection.ie, 21 Fitzwilliam Square South, Dublin 2, D02 RD28), to your local EU authority, or, in the UK, to the ICO (ico.org.uk).
Go to Settings and choose Delete account. This immediately deletes your account data, apart from the shared public-game cache described in section 2, and cancels a website plan. Deleted data leaves our backups within 30 days.
Chester is for people aged 13 and over, and anyone under 18 needs a parent or guardian's agreement. If we learn we hold data from a child under 13, we'll delete it.
We'll tell you about significant changes to this policy before they apply.
Every move checked by Stockfish, with blunders, best moves and your accuracy. Free and unlimited.