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OMSR Chess is a free chess learning website. You may use it for personal, non-commercial learning and play. No account is required, and there is no paid tier — every opening, lesson, puzzle and bot level is available to everyone.
Your progress lives in your browser, not on our servers. We are not able to recover it if you clear your browser data, use a different device, or browse privately. Export it from the Profile screen if it matters to you. We provide no backup guarantee.
The site is supported in part by advertising. The "hearts" mechanic limits how many mistakes you can make in a session before pausing. Hearts refill automatically over time at no cost. You may optionally watch a short advertisement to refill them sooner; this is never required, and hearts always refill on their own over time. We may change the number of hearts, the refill rate, or the reward amount at any time.
Using an ad blocker will not restrict your access to any part of the site.
Donations are entirely voluntary and buy no additional features, content or privileges — there is nothing extra to unlock. They go toward keeping the site running and improving it. Donations are processed by the platform you choose and are, by their nature, non-refundable; if you donated in error, email us and we will try to help.
Don't attempt to break, overload or resell the service, don't scrape it wholesale, and don't circumvent the advertising mechanisms. The chess content is provided for your own study.
The openings, evaluations and lesson material are provided in good faith and are machine-verified for legality, but chess theory is large and opinions differ. Nothing here is guaranteed to be objectively best play, and no rating improvement is promised.
The site is provided "as is" and "as available". We do not guarantee it will be uninterrupted or error-free. We may change or discontinue features at any time. Once loaded, the app continues to work offline, so temporary outages need not interrupt your study.
To the maximum extent permitted by law, our liability arising from your use of this free site is excluded. Nothing here excludes liability that cannot lawfully be excluded.
This document is a practical starting point, not legal advice. Have a lawyer review it before you rely on it commercially.