# Free BPM and key finder: works in your browser, nothing is uploaded

> Drop in a song, a beat or a vocal and get its tempo in BPM and its musical key in seconds. Runs in your browser: the file never leaves your device.

Source: https://lyromusic.com/tools/bpm-key-finder

# Free BPM and key finder

Drop in a song, a beat or a vocal and this tool tells you its tempo in beats per minute and its musical key. The analysis runs in your browser, so the file never leaves your device and there is nothing to sign up for.

**Drop an audio file here, or choose one** WAV, MP3, FLAC, M4A or OGG, up to about ten minutes.

**0** Tempo (BPM)

**-** Key

Tap along to the beat.

Make a beat that fits this vocal, or a vocal that fits this beat. [Start on Lyro](https://lyromusic.com/start?have=vocal)

## Questions

### How does the BPM finder work?

It measures how the energy of the audio changes over time, finds the regular pulse in those changes, and converts the pulse to beats per minute. Drums make this easy. A solo vocal has a weaker pulse, so check the result with tap tempo.

### How is the key detected?

The tool adds up how much of each of the twelve notes is present across the track and compares that fingerprint with the typical fingerprint of every major and minor key. The closest match wins, and the runner-up is shown because relative keys, such as A minor and C major, share the same notes.

### Is my file uploaded?

No. The file is decoded and analysed inside your browser. Nothing is sent to a server.

### Why does it say double or half the tempo I expected?

Tempo has octaves, like pitch. A 70 BPM trap beat can be counted as 140. If the number looks doubled or halved, it usually is: both are valid ways to count the same track.