The Chord Trainer drills chord spelling across all 12 roots and every common chord quality — major, minor, diminished, augmented, dominant 7, major 7, minor 7, half-diminished, diminished 7, major 9, dominant 9, minor 9, add9, major 11, minor 11, major 13, dominant 13, and minor 13. Pick the qualities you want to practice on the setup screen and the deck builds itself; toggle 7ths off if you only want triads, or turn on the 9ths and 13ths once the basics feel automatic.
Each card runs in one of two directions. Spell the chord shows a chord name (like B♭madd9) and asks you to enter the notes — perfect for building active recall. Name the chord shows you the notes and asks you to identify what they spell — the skill you need when analyzing a piece or transcribing music.
Four input modes mean you can practice on whatever surface fits your instrument: tap selectors for fast typing, music staff for sight-reading practice, piano keyboard for piano players, and guitar fretboard with curated real-world fingerings (open chords, E-shape and A-shape barre voicings, and shell voicings for 11ths and 13ths) for guitarists.
Chord recognition is a recall task. The faster you can spell a B♭maj9 in your head, the more attention you can spend on phrasing, voicing, and feel when you actually play. Drilling also builds the spelling discipline — knowing that the third of D major is F♯ (not G♭), that the diminished triad uses two minor thirds, that the 13th of a dominant 13 chord is the major sixth above the root.
Best times are tracked per setup so you have a target to beat, and every wrong answer adds 20 seconds — encouraging accuracy over speed. The trainer is free, runs in your browser, and requires no account.