Tempo (BPM) and key come up constantly: to build a mashup, place vocals in tune, sync to video or set the tempo in a Suno prompt. You can detect them in seconds — no software to install.
Why BPM and key matter
Mixing and mashups — tracks must match in tempo and key.
Suno prompt — putting the BPM in a style descriptor sets the tempo you want.
Vocals and instruments — knowing the key keeps overdubs in tune.
Ways to find the BPM
You can count beats by hand (beats in 15 seconds × 4) or tap the tempo on a key — but that is rough and tedious. Faster and more accurate is to run the file through an analyzer that computes tempo from the waveform.
How to find the key
Finding the key by ear is hard even for musicians. An analyzer breaks the track down by spectrum, finds the tonic and mode (major or minor) and returns a ready answer, for example “A minor”.
The fastest way
Our free track analyzer does it all at once: drop a file and get BPM, key and loudness in a couple of seconds. It runs on the Essentia.js engine right in your browser, so the file never leaves your device and the answer is instant.
🎼 Track Analyzer — free
BPM, key and loudness in seconds. In the browser, nothing uploaded.
The analyzer computes tempo from the beat and key from the spectrum and is usually spot on for rhythmic material. Floating tempo or very complex harmony can introduce error — trust your ear as the final judge.
What files can I upload?
MP3, WAV, M4A, FLAC. Processing runs in the browser and the file never leaves your device.
Why do I need BPM and key for Suno?
Putting the right BPM in a style prompt tells Suno the tempo, and knowing the key helps you build mashups and place vocals in tune.
Is it free?
Yes, the track analyzer is free and needs no sign-up.