Chordify Its not a solution for all songs, but its helpful in keeping time
many of youtube video that shows the chord progression does not match what chordify transposes.
Automatic chord extraction/estimation is a hard task with plenty of active academic research (see, for example, the MIREX Audio Chord Estimation track). Chordify uses state-of-the-art music recognition software, but it often fails to find the correct chords or beat. We are continuously improving our service, and keep up-to-date with the latest developments in the field, to offer the best user experience possible.
All the best,
The Chordify team