BPM and key finder online — free
Quick answer Upload a song or loop and get an estimate of its tempo in beats per minute and its musical key.
Estimate the tempo (BPM) and musical key of a song or loop. Works best on music with a steady beat; 5 seconds to 10 minutes. 15MB max (Pro: 20MB).
Free to try · No signup required · Commercial use allowed · How we test · About VoxCraft
Find the BPM and key of a song online for free with VoxCraft. Upload an MP3, WAV or other audio file and get an estimated tempo and musical key in a few seconds — no install and no signup on the free tier.
Knowing the tempo and key makes mixing and remixing far easier: DJs match tracks by BPM and key, producers pick loops that fit a project, and singers check whether a song sits in a comfortable key. Runners and dancers use BPM to pick music at the right pace.
Both numbers are estimates. The tempo comes from beat tracking, which sometimes lands on half or double the tempo you actually feel (a 70 BPM ballad detected as 140, for example), so the result also shows the half and double values to try. Key detection works from the notes present across the whole file and is most reliable on melodic music; it is weak on speech, drums-only audio, or songs that change key.
To analyse just one section, cut it with the trim tool first. To change a track's tempo afterwards, use Change audio speed.
How it works
- Upload a song, loop or recording (15MB max, 20MB with Pro; 5 seconds to 10 minutes long).
- Tap Find BPM & key and wait a few seconds.
- Read the tempo and key. If the tempo feels half or double, try the alternative values shown.
- Check by tapping along or playing the track against a metronome.
Who uses this
DJs and remixers
Match tracks by tempo and key so transitions and mashups sound in tune.
Producers
Pick samples and loops that fit the tempo and key of your project.
Singers and musicians
Find the key of a backing track so you can choose a comfortable range.
Workouts
Find the BPM of a song to match it to your running or training pace.
Tips for better results
- Use a section with a clear, steady beat; long intros and breakdowns make estimates less reliable.
- If the tempo seems to be half or double what you feel, try the alternative values.
- Songs with tempo changes return a single average estimate.
- Treat the key as a good starting point and confirm it by ear against a keyboard or tuner.
Frequently asked questions
How accurate is the BPM?
Usually close on music with a steady beat, but beat trackers sometimes report half or double the felt tempo. The result shows those alternatives.
How accurate is the key?
Reasonable on melodic music; unreliable on speech, percussion-only tracks and music that modulates. Confirm by ear.
What files can I use?
Common audio formats such as MP3, WAV, M4A, OGG and FLAC, up to 15MB on Free (20MB with Pro) and 10 minutes long.
Can it detect the BPM of a voice recording?
Speech has no steady beat, so any result will be unreliable.
Is it free?
Yes within free-tier limits, with no account required to start.