Estimate the tempo (BPM, beats per minute) of a music track locally in your browser - for DJ sets, fitness playlists or production. No upload.
Running locally on your device ...
Running locally on your device ...
0%
Your files never left your device
No. Everything runs in your browser - your file never leaves your device. How this is verifiable
Mixing two tracks seamlessly at the same tempo while DJing, sorting a playlist by rising intensity for a workout, or simply being curious how fast a favourite song actually is - all of that needs a BPM value (beats per minute). This tool estimates it directly from the audio file, with no server database or music-recognition service involved.
The estimate follows a classic approach from music information retrieval: first an energy envelope is built from the signal (how loud is it in short time windows), then an onset curve from that (where does it suddenly get louder - typically at a beat), and an autocorrelation then searches for the interval that repeats most regularly. That interval yields the estimated tempo.
Important, said honestly: the result is an algorithmic ESTIMATE, not an exact measurement - for music with an unclear or shifting beat (ambient, free-form drumming, or a tempo change within the track), the value can be off. A confidence percentage in the result shows how clear-cut the detected pattern was.
| Input formats | MP3, WAV, M4A, AAC, OGG, OPUS, FLAC |
|---|---|
| Auto-conversion | MP4 |
| Output format | TXT |
| Batch processing | No |
| Processing | Locally in your browser (WebCodecs) |
| File upload | None |
Limitations: The result is an algorithmic estimate (onset autocorrelation), not a precise measurement - for music without a clear, steady beat it can be off. Very short clips (under 3 seconds) are refused with a clear message because there is too little structure for an estimate. Honest per-device length cap applies as for every audio tool.
No, the analysis runs entirely locally in the browser.
No, it is an algorithmic estimate. The stated confidence value shows how clear-cut the detected pattern was.
Music without a clear, steady beat (ambient, free-form playing, tempo changes) is hard for any algorithm to estimate.
Yes, the sibling tool "Find the key" estimates the root key instead of the tempo.
Find the key · Create a spectrogram · Create a waveform image · Reverse audio