BPM & Key Detector
Analyze any audio file to detect its tempo (BPM) and musical key — entirely in your browser.
Your file is analyzed entirely in your browser — nothing is uploaded to our servers.
Drop an audio file here
Or click to browse — we detect the tempo and musical key locally.
Choose a fileSupports MP3, WAV, OGG, M4A, FLAC and more.
Analyzing your track…
Pitch class profile
Relative energy per noteThese results are automated estimates and may differ from the true tempo or key, especially for complex or ambiguous tracks.
About BPM & Key Detector
The BPM & Key Detector analyzes any song and reports its tempo in beats per minute and its musical key. Drop in an MP3, WAV, OGG, M4A, or FLAC file and the tool decodes it, detects the beat spacing to estimate BPM, and correlates the harmonic content against key profiles to name the most likely major or minor key.
Results come with a confidence rating, half-time and double-time alternatives for the tempo, and a pitch class profile chart showing the relative energy of each note — useful context when a track is rhythmically or harmonically ambiguous. A copy button puts the BPM and key straight on your clipboard.
Everything happens locally in your browser using the Web Audio API: the file is decoded and analyzed on your machine and never uploaded. That makes it a fast, private way for DJs, producers, and remixers to find the key and tempo of a song.
How to use BPM & Key Detector
- Drop an audio file onto the page, or click to browse and choose one.
- Wait a few seconds while the track is decoded and the tempo and key are detected.
- Read the BPM, the detected key, and their confidence ratings.
- Check the half-time and double-time alternatives if the tempo feels off.
- Copy the results to your clipboard, or analyze another track.