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ECO opening explorer
Search all 3,810 named lines across 149 families and every ECO code, A–E. Play any
line on the board, or paste a FEN or PGN below to identify a position. Source: the
CC0-licensed lichess.org opening database .
This tool needs JavaScript to search and play. Browse the
full ECO index or jump straight to a family guide below --
every line is also listed there as plain text.
cm-chessboard pieces and markers sprite
Chess pieces and markers for the cm-chessboard (https://shaack.com/projekte/cm-chessboard/).
Identify a position from a FEN or PGN
Or browse by family
Sicilian Defense
391 lines, ECO B20–B99 Ruy Lopez
235 lines, ECO C60–C99 French Defense
212 lines, ECO C00–C19 Queen's Gambit Declined
198 lines, ECO D02–D69 Italian Game
187 lines, ECO C50–C59 English Opening
175 lines, ECO A10–C20 King's Gambit Accepted
137 lines, ECO C33–C39 King's Indian Defense
119 lines, ECO E60–E99 Caro-Kann Defense
110 lines, ECO B10–B19 Nimzo-Indian Defense
99 lines, ECO E20–E59 Queen's Pawn Game
82 lines, ECO A40–D05 Dutch Defense
69 lines, ECO A80–A99 All 149 families and ECO volumes →