BPM DetectorDetect the tempo (BPM) of any audio or music file.
BPM Detector
Detect the tempo (BPM) of any audio or music file.
Upload Audio
Drop your music or audio file or click to browse.
Detect BPM
Click Detect to analyze the tempo of your audio.
View Results
See the detected BPM and tempo analysis results.
What Is BPM Detector?
The BPM Detector analyzes audio files to detect the tempo in beats per minute (BPM). Upload any music file and the tool will analyze the rhythmic content to determine the BPM. This uses onset detection and autocorrelation algorithms implemented with the Web Audio API. The detector works best with rhythmic music but can also analyze spoken word and other audio. Results include the detected BPM, confidence level, and tempo classification (e.g., Allegro, Moderato). Essential for DJs, music producers, and anyone who needs to know the tempo of a track.
Why Use Our BPM Detector?
- Accurate BPM detection using multiple analysis algorithms
- Works with any audio format (MP3, WAV, OGG, etc.)
- Shows confidence level and tempo classification
- Completely browser-based — no uploads needed
Common Use Cases
DJing
Determine track BPMs for beat-matching and playlist organization.
Music Production
Find the tempo of samples, loops, and reference tracks.
Exercise Playlists
Sort music by BPM for running, cycling, or workout playlists.
Music Theory
Analyze and study the tempo of different musical pieces and genres.
Technical Guide
The BPM detection uses a multi-stage algorithm. First, the audio is decoded into an AudioBuffer and mixed to mono. A lowpass filter emphasizes bass frequencies where beats are most prominent. The filtered signal undergoes onset detection: the audio is divided into windows, and the spectral flux (change in energy between consecutive frames) is calculated. Peaks in the onset detection function correspond to beats. The inter-onset intervals are then analyzed using autocorrelation to find the most common periodicity, which gives the BPM. The autocorrelation function R(τ) = Σ x(n) * x(n+τ) reveals the dominant periodicity. The BPM is calculated as 60 / peakPeriod. Multiple candidate tempos are evaluated and the most statistically consistent one is selected. The confidence score reflects how clearly periodic the rhythm is.
Tips & Best Practices
- 1Works best with music that has a clear, steady beat
- 2Rock, pop, electronic, and hip-hop typically give the most accurate results
- 3Classical music and jazz with tempo changes may give less reliable results
- 4If the detected BPM seems half or double the actual tempo, it's a common octave error — just multiply or divide by 2
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Audio ToolsFrequently Asked Questions
QHow accurate is the BPM detection?
QWhat is BPM?
QWhy does it sometimes show half/double the expected BPM?
QDoes it work with vocal-only tracks?
QIs my music uploaded?
About BPM Detector
BPM Detector is a free online tool from FreeToolkit.ai. All processing happens directly in your browser — your data never leaves your device. No registration required. No ads. Just fast, reliable tools.