Free Online Song Key Finder — Detect Any Song's Key
Drop a song and get its musical key (tonal center) and BPM in a few seconds. No signup, no quota — analyzed on our private GPU server and deleted instantly.
How to find a song's key
- Upload the song — drag it onto the box above or click to choose a file.
- Wait a few seconds while our server analyzes the harmonic content (chroma) of the audio.
- Read the key — the estimated tonal center, BPM, and duration appear instantly.
Who uses a key finder?
- Singers — check whether a song sits in your vocal range before performing.
- DJs — mix in key (harmonic mixing) for smoother transitions.
- Producers & remixers — match a sample or acapella to your project's key.
- Cover artists — find the original key, then transpose to suit your voice.
- Music students — analyze songs and train your ear.
How key detection works (and its limits)
We compute the chroma — the energy in each of the 12 pitch classes — across the whole recording, and report the strongest as the tonal center. This gives you the root note of the song. It does not yet distinguish major from minor, and very chromatic, atonal, or key-changing songs are harder to pin down. For a cleaner harmonic reading on a busy mix, first extract the instrumental and analyze that — removing the vocal often sharpens the chroma profile.
Frequently asked questions
Is the key finder free?
Yes — free, no signup, no daily quota. Only rate-limited to prevent abuse.
Does it tell major vs minor?
Not yet — it reports the tonal center (root note). Major/minor distinction is on the roadmap.
How accurate is it?
Good for clearly tonal music; harder for atonal, heavily processed, or key-changing songs.
Does it show BPM too?
Yes — tempo is shown alongside the key. See the dedicated BPM Detector.
Do you keep my file?
No — analyzed and deleted immediately, never stored or used for training.
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Want the instrumental or acapella too?
🎙️ Open the AI Vocal RemoverStudio-grade separation · free 1 song/day