Frettle

A fretboard visualizer for guitar, bass, ukulele and mandolin. Pick a chord or a scale and see where every note sits on the neck.

• Shows every note on the neck for guitar (6 or 7 strings), bass (4 or 5 strings), ukulele (standard and baritone) and mandolin
• Common alternate tunings: guitar Drop D, DADGAD, open G, half step down and a few more, ukulele high or low G
• Chords: pick a root and a type, then flip through the shapes up the neck. Each note shows its interval (R, 3, 5...) and barres are drawn in
• Scales: the modes, minors, pentatonics, blues and a few more, with the triads that fit. You can split the scale into hand-sized groups or hide the notes outside it
• Capo, octave shading, a left-handed mode, and tap any note to hear it or strum the whole chord
• Tells you when a chord fits the scale you picked
• Spells notes for the key, so you get F♯ in D major and B♭ in F major
• Built for phones first, works offline once loaded, and can be added to your home screen (PWA)