Key finder: find the key of any song
Free, no signup. We analyse the whole track, not a clip, and show the BPM as well.
Find key & BPM
Check one song's key and tempo, free.
We don't train models on your audio. Privacy policy
How accurate is it?
When it answers, it's right about 80% of the time. It answers on about 44% of songs. Below its confidence threshold it tells you so rather than guessing. How we measured it.
Tempo and key detection: Beat This! (Foscarin, Schlüter & Widmer, CPJKU); S-KEY (Kong et al., Deezer)
Need the vocals or the instrumental on their own? Try the vocal remover.
How to find the key of a song
- 1
Upload the track
Choose an audio file, up to 10 minutes and 120 MB. No account is needed.
- 2
Read the key, or why there isn't one
When the model is confident it names the key, such as A minor. When it isn't, it says so instead of guessing.
- 3
Check it on an instrument
Play the key's root chord over the chorus. If it sounds settled, the key is right. If it sounds tense, try the relative major or minor.
Why it sometimes won't name a key
It names a key on about 44% of songs. On the rest, the model's confidence is below the threshold we set, and the page tells you it isn't sure. We chose that trade so that a key it does show is right about 80% of the time.
Songs that change key, modal songs built on Dorian or Mixolydian, and tracks that sit on one riff without much chord movement are common reasons for a low-confidence answer.
Relative keys use the same notes, so C major and A minor are a common mix-up for any key detector. Listen for the chord the song comes home to at the end of a section.
It reports one key for the whole file. If only the last chorus moves up a step, the answer describes the rest of the song.
Frequently asked questions
How do I find the key of a song?
Upload the song above. StemX listens to the whole track and shows its musical key, usually within a few seconds.
Why does it sometimes say it isn't confident?
It only names a key when the model's confidence is high. That is how it keeps its precision at about 80%; below that threshold it tells you so rather than guessing.
How accurate is it?
When it answers, it's right about 80% of the time. It answers on about 44% of songs.
Is it free?
Yes. You can check up to 20 songs a day without an account. Files can be up to 10 minutes and 120 MB.
Does it also find the BPM?
Yes. Results usually show the tempo too, in beats per minute, with half and double time alongside.
What can I use the key for?
Mixing in key as a DJ, choosing a capo position or transposing a song to suit your voice, setting a scale in your DAW before you write a part, or finding a backing track that fits.
Does it work on my own recordings?
Yes. It reads the file itself, so a rehearsal recording, a demo or a stem from a split works as well as a released song.
Does it say major or minor?
Yes. A key always comes with its mode, such as F# major or D minor. It names major and minor keys only, so a modal song is reported as the closest major or minor key, or as not confident.