Enter the chords from a song. The tool checks them against all 24 major and minor keys and shows you the most likely match. Useful when learning covers, writing originals, or just trying to understand the harmony.
1. Choose a Root Note
2. Choose a Quality
Your Chords
Enter your chords and the tool compares them against all 24 major and minor keys. It checks which chords are diatonic to each key and ranks results by match percentage. The top result is your most likely key. Below that you get a breakdown of matched chords versus any that might be borrowed from another key.
Figure out the chords in the song, even if you only have a few. Enter them here and the tool ranks every key by how many match. The one at the top is almost certainly your key.
It tells you which scales to solo over, lets you transpose to a better vocal range, and gives you a shared language with other musicians. It also helps predict chord changes, which is useful for writing bass lines, melodies, or harmony parts.
C major, G major, D major, A major, E minor. These keys dominate because they are full of easy open guitar chords, they work well on piano, and most singers are comfortable in those ranges.
Yes, and it happens constantly. Borrowed chords from parallel keys, secondary dominants, modal interchange. Do not worry if one or two chords do not fit neatly into the top result. The key with the highest match percentage is still your best bet. The outliers are borrowed chords.