About the project

Debutario is a website where you build your own opening repertoire and work out why every move belongs in it. The repertoire builder suggests continuations from the statistics of games played at your level, shows where your repertoire still has gaps, and helps you retain the lines with spaced-repetition practice. The repertoire within the free saved-move limit and practice work without an account. Sync across devices is also free, but requires an account.

The second part of the site is interactive chess opening lessons for beginners and club players. The lessons are narrated: the teacher explains the idea behind every move in words and shows the lines on the board, waiting for your move at key positions. Some courses have their first lessons open to everyone without an account; PRO Lessons gives full access to every course.

The course lines are selected from a corpus of real games and verified with Stockfish engine evaluations: the lessons include continuations that are actually played and confirmed by analysis. Typical amateur mistakes — frequent yet weak moves — are covered separately.

Every move explanation is written out and voiced, so a course feels like an in-person lesson: you listen and watch the board. The narration is read by a synthesized voice, not a human narrator; occasional stress errors are possible, which is why the text is always duplicated on screen. In the English version the text is read aloud by your browser.