Key finder from chords
Enter the chords you have. The tool lists major and minor keys that contain them, including relative pairs that share the same chords. It does not listen to audio and it will not invent one true key when two fit.
Add chords
Quality first, then tap a root. Tap a selected chord to remove it.
Selected
Possible keys
How to read the list
C, F and G fit both C major and A minor. Choose by the chord that feels like home, not by counting major versus minor shapes. An E major after A minor is often V in harmonic minor, not proof of E major as the key. Borrowed chords are listed instead of being forced into one scale.
To estimate key from a recording, use the audio analyzer. For listening steps, see how to find the key of a song.