BPM Detector Online
Find the tempo of any music file in seconds. Drop a song in, get the BPM out — onset-energy autocorrelation, all in your browser.
Tempo Reference
Where common genres and feels live on the BPM scale.
Why Notevibes BPM Detector
Onset-energy autocorrelation, in your browser.
Onset-Energy Algorithm
Computes the energy envelope, takes positive differences for onsets, autocorrelates for tempo. Standard music-IR approach.
Instant Result
Detection runs in seconds for typical 3-minute tracks. No waiting, no progress bar.
Privacy First
Audio is processed locally in your browser. Nothing is uploaded — only the BPM number shows.
Any Audio Format
MP3, WAV, M4A, FLAC, OGG, AAC up to 200 MB.
Tempo Categories
Get a genre/feel label alongside the number — Slow, Mellow, Mid, Up-tempo, Fast, Very fast, Extreme.
Works on Mobile
Detect BPM on any phone or tablet. iOS, Android, all major browsers.
Your Audio Stays on Your Device
DSP runs in JavaScript. Nothing is uploaded — only the BPM number shows.
No Upload
File never leaves your device
No Account
Start detecting immediately
No Tracking
We never see your audio
When to Detect BPM
Best on music with a clear, steady beat.
DJ track prep
Get exact BPMs for harmonic mixing and beat-matching
Sample matching
Find the BPM of a sample so it fits your project tempo
Rap / spoken word
Lock in a backing track at the right speech tempo
Video editing
Sync cuts to the beat — find the music's BPM first
Workout playlists
Build pace-targeted runs / cycling sets at consistent BPMs
Cover songs
Match an original's tempo when learning or covering a track
Want to Change the Tempo?
Once you know the BPM, use the Notevibes Tempo Changer to retime music while keeping pitch — perfect for DJ practice and beat-matching.
Open Tempo ChangerFrequently Asked Questions
What is BPM?
BPM stands for Beats Per Minute — a measurement of musical tempo. A song at 120 BPM has two beats every second. Most pop and rock songs sit between 90 and 130 BPM; dance music typically lives between 120 and 140 BPM.
How does this BPM detector work?
It computes a moving energy envelope across short audio frames, takes the positive differences (onset envelope), and autocorrelates that envelope. The autocorrelation peak in the 60–200 BPM lag range gives the most likely tempo.
How accurate is it?
For music with a clear, steady beat (most pop, rock, electronic, hip-hop), accuracy is within ±1 BPM. Detection can land on a tempo multiple (e.g. half or double) when the beat structure is ambiguous — common with shuffle and triplet feels.
What kinds of audio work best?
Music with strong rhythmic content — drums, percussion, regular bass — is detected most reliably. Free-time material (classical orchestra, ambient, spoken word) does not have a meaningful BPM and may give noisy results.
Why did I get half or double the expected BPM?
Beat tracking is inherently ambiguous when a song has strong half-time or double-time pulses. If you got 75 BPM but expected 150, just double it — the detector locked onto a sub-beat. To re-time your audio after, use the tempo changer.
Is the BPM detector free?
Yes. Completely free with no sign-up, no watermark, and no limits. Max file size is 200 MB.
Is my audio file uploaded to a server?
No. The detector runs entirely in your browser. Your file never leaves your device — only the BPM number is shown.
What audio formats are supported?
MP3, WAV, M4A, FLAC, OGG, and AAC. Anything your browser can decode will load.
Does it work on mobile?
Yes. It runs on Chrome, Firefox, Safari, and Edge on both desktop and mobile.