Local and private
The browser decodes and analyzes the file on your device. The audio is not uploaded to Find Music By Sound or a recognition provider.
BPM & KEY FINDER
Find the BPM and key of any song
Analyze tempo and the dominant musical key from an audio file. The calculation runs on your device, so your track never leaves the browser.
USE THE TOOL
Upload a track to detect tempo and key
Best with a steady beat and at least 20 seconds of tonal music.
Private by design · 1 creditGoogle sign-in is required, but your audio is analyzed in this browser and never uploaded.
WHY USE THIS TOOL
Useful answers without hiding the uncertainty
Rhythm plus harmony
Get a BPM estimate, tempo confidence, major or minor key, and tonal confidence from the same analysis.
Honest about ambiguity
Half-time rhythms, live timing, modulation, and percussion-only files can produce more than one valid interpretation, so confidence stays visible.
HOW IT WORKS
From input to answer
- 01
Choose a representative section
Use a track with a clear beat and stable harmony. A verse and chorus together usually reveal more than a short intro.
- 02
Run the local analysis
The tool measures onset timing for tempo and compares the chroma profile with major and minor key templates.
- 03
Check by ear
Tap along to confirm the BPM and test the detected key in your DAW, instrument, or harmonic-mixing workflow.
REFERENCE
What this tool returns, and where it stops
Tempo estimate with a confidence figure
The BPM is estimated from rhythmic onsets in the audio, searching a 60–200 BPM range. Half-time and double-time readings are common on some genres, so compare with how the track feels.
Musical key with a confidence figure
The key is estimated by comparing the pitch-class content of the audio with major and minor key profiles. Related keys (relative major/minor) are the usual source of mistakes.
Input, handling and cost
- Input
- An audio file chosen from your device
- What is analysed
- The first three minutes of the file, decoded in your browser
- File handling
- Not uploaded; analysis runs locally
- Cost
- 1 credit. The file is decoded in your browser and is not uploaded.
Known limitations
- Tempo changes, rubato performances and tracks with a weak beat give unreliable BPM figures.
- Key detection is least reliable for atonal music, heavy distortion, percussion-only material and tracks that modulate.
- A single analysed section may not represent the whole song, because only the first three minutes are used.
- For critical DJ or production work, confirm by ear or with a reference in your DAW.
QUESTIONS, ANSWERED
Frequently asked questions
Why can BPM appear half or double the expected value?
The same pulse can be counted at different metrical levels. A 70 BPM half-time groove may also be described as 140 BPM.
Can a song have more than one key?
Yes. Songs can modulate, use modal harmony, or contain ambiguous chords. This tool reports the dominant profile across the analyzed audio.
Is my audio uploaded?
No. File decoding and signal analysis happen locally in the browser.