Instantly detect the tempo (BPM) and musical key of any track. Just drop in a file — analysis runs automatically, privately, in your browser.
Open the Audio Studio
Go to the DefyAudio Studio.
Upload your song
Drop in an MP3, WAV, FLAC or other audio file.
Read the analysis tiles
The Tempo (BPM) and Key are detected automatically and shown alongside loudness, duration and format.
Use it
Match tracks for a DJ set, set a metronome, or transpose to a target key — all in the same tool.
Automatic BPM
Tempo is estimated from the track's rhythmic energy — no tapping required.
Musical key
Detects the major/minor key so you can mix and transpose confidently.
Analyze then act
Right there in the Studio you can also pitch-shift, trim, and convert.
BPM (beats per minute) is the tempo of a track, and the key is its tonal center — the two numbers DJs, producers and musicians need to mix, mashup, or play along. DefyAudio detects both automatically the moment you load a file: tempo from the rhythmic onset pattern, and key from the track's harmonic content.
Everything runs locally in your browser, so analysis is instant and private. And because you're already in the Studio, you can act on the result immediately — transpose to a new key, time-stretch, or trim a loop.
Upload the song to DefyAudio's Studio — the tempo is detected automatically and shown in the Tempo tile, no tapping needed.
Yes — the Key tile shows the detected major or minor key alongside the BPM.
BPM is usually accurate within a couple of beats; on some tracks it may report a half- or double-time value. Key detection works best on tonal music and may be less certain on spoken word or noise.
No — analysis runs in your browser, so the file never leaves your device.