Help & FAQ

A chess opening trainer. You study a prepared line on an interactive board, learn why each move is played, then play that line back from a blank board without help. Alongside the openings there is an endgame vault, over 99,000 tactics puzzles, and Stockfish game review.

No. The Fried Liver Attack course is open without signing in, and the king-and-rook and king-and-queen mate drills in the Endgames Vault are free to guests too. An account saves your progress, unlocks the free Vienna, Jobava, and London System courses, and keeps your puzzle rating and practice streak.

The Fried Liver Attack course, the two basic mate drills, and the puzzles are free. Once you sign in you also get the Vienna, Jobava London, and London System courses, one opening course you can build yourself, one official course completion, unlimited Stockfish game reviews, and one Chess.com or Lichess stat checkup a day.

No. The endgame vault starts with the basic mates, puzzles are matched to your own solving rating, and the courses cover systems that show up at club level: the Italian, the London, the Caro-Kann, the Sicilian, and more. The trainer also explains the idea behind a move rather than only listing moves, so you are not expected to already know why it is played.

Accounts have to confirm an email address first. We send a six-digit code - check your inbox, spam, and trash - and signing in stays blocked until that code is entered. If the code expires, request a fresh one from the verification screen.

Plus (EUR 3.20 or USD 3.99 a month) raises the free limits: 15 of your own courses, 25 official course completions, the full Insights report on every game you review, unlimited stat checkups, publishing courses to the Community library, custom avatar frames, and every official course as it ships. Unlimited (EUR 5.90 or USD 6.99 a month) removes the caps and raises your own courses to 60.

The Fried Liver Attack is free to everyone, including guests. After you sign in, the Vienna Opening, the Jobava London System, and the London System are free as well. Everything else in the library needs a paid plan.

Yes, and they are deliberately small but real: one course you create yourself, one official course completion, and one stat checkup a day. Game reviews are unlimited once you sign in, on any plan. Puzzles are unlimited. Progress on your own courses is always uncapped - the limit only applies to official courses.

Yes - a free day, claimed once per account, which unlocks everything the Unlimited plan includes for 24 hours: all official courses, unlimited game reviews, and unlimited stat checkups. No card is asked for, nothing is subscribed, and nothing converts automatically; it simply expires. You cannot claim it twice, and you cannot claim it while a paid plan is active.

Your own course completions are always unlimited, whatever plan you are on - your courses, your pace. Paid plans raise how many courses you can create: 1 free, 15 on Plus, 60 on Unlimited.

There is a free tier that never expires and needs no card. Paid plans are monthly subscriptions through Stripe: Plus at EUR 3.20 or USD 3.99, and Unlimited at EUR 5.90 or USD 6.99. You can switch the displayed currency between EUR and USD on the plan page before you check out.

Pick Plus if you want more than the free tier: 25 official course completions, 15 of your own courses, and the Insights report on every game you review. Pick Unlimited if you want to finish the whole official library, or need more than 15 courses of your own - it allows 60.

From your profile, where the plan is managed. You can also email us and we will cancel it for you. Access continues until the end of the period you have already paid for; it does not stop the moment you cancel.

Yes. Both plans are monthly subscriptions, so they renew on the same day each month until you cancel. Cancelling before the next renewal date stops the following charge.

Unless the law where you live requires otherwise, fees are not refundable once a billing period has started. If something went wrong with a payment, email us and we will look at it - we would rather sort out a mistake than argue about it.

Payments are processed by Stripe and appear under the descriptor OPENINGMATRIX. OpeningMatrix never sees or stores your card number - it is entered on Stripe's own checkout page.

Four, and they build on each other: Browse puts the line on the board so you can look at it; Learn plays through it with a comment explaining each idea; Practice asks you for the next move with no help shown; and Time trial is Practice against a clock.

Because it is the mode that measures whether you actually know the line, so we keep the result against your account. Browsing, learning, and practising all work without an account.

Yes. Every course can be drilled as White or as Black, and you can flip sides at any point. Playing the other side is also a good way to understand what your opponent is trying to do.

If you are signed in, yes - mastered lines, your practice score, and your streak are stored on your account, and each course card shows how much of it you have finished. If you are not signed in, progress is kept only in your own browser and is lost if you clear it or switch device.

Yes. The repertoire builder lets you create your own courses, branch them into variations, and drill them in the same trainer with the same modes. Your first course is free, and you can keep it private or publish it so other people can train it too.

Chess.com and Lichess. You add a username on your profile page - there is no password to hand over, because both sites expose the games and ratings we use through their public APIs.

A free account can run one checkup per day. Plus and Unlimited have unlimited checkups, so you can refresh as often as you like.

No. We only read what the platforms publish publicly for the username you give us. Nothing is posted back to Chess.com or Lichess, and we never ask for your password on either site.

Yes. On the game review page you can paste a PGN directly, and on Blunder Override you can paste a game instead of scanning a username.

Use the reset link on the sign-in page and we will email you a reset. Passwords are handled entirely by our authentication provider - we never see or store your password.

Email us from the address currently on the account and we will change it. There is no self-serve email change yet, because the address is what proves the account is yours.

Open Account on this site and use the Delete account card at the bottom. You confirm with your password, and we remove your profile, your @handle, any opening courses you created (including ones published to the Community library), your practice and puzzle progress, and your leaderboard entries. It is permanent and cannot be undone. If you have an active paid plan it is cancelled as part of the deletion, so you are not billed again; any unused part of the current period is not refunded.

Your handle, your display name, any courses you choose to publish, and your place on the leaderboards. Your email address is never shown to anyone else, and courses you keep private stay private.

One essential session cookie that keeps you signed in, plus a little local storage in your browser for your theme and any progress made while signed out. There is no advertising code and no third-party analytics on the site, so there is no consent banner to click through - the only cookie is the one the site cannot run without.