BPM Detector
Detect the tempo, duration, sample rate, channels and bitrate of any audio file — on the server
🎵 Upload any audio file and the server will analyze its tempo, duration and technical specs using FFmpeg analysis tools.
⚠️ Please don't close or refresh this page until it's done, or you may lose the result.
💡 Large files travel at your connection's pace: the upload continues on its own and resumes safely, so a slow link only affects time, never your credits.
How it works
- 1
Upload any audio file — format doesn't matter, the server decodes it.
- 2
Click "Analyze BPM" — the server runs ffprobe metadata analysis and FFmpeg BPM detection.
- 3
Read the results on the page: BPM, duration, sample rate, channels, bitrate and codec. Files auto-delete in 30 minutes.
Tempo detection you can verify by ear
Get BPM plus a confidence score and tap-override — because algorithms deserve a sanity check just like humans do.
Tempo From FFmpeg
FFmpeg's bpm filter analyzes the beat on our server, so you get an accurate tempo reading for any upload — the number DJs need before a mix.
Full Technical Spec
Alongside the tempo, ffprobe reports duration, sample rate, channel count, bitrate and codec — everything about the file in one readout.
No Output File Needed
The analysis returns a summary only — no converted file, no re-encoding — just the numbers, straight from the uploaded source.
Onset-detection method, step by step
The analyzer works on the VPS in four stages:
- Onset envelope — spectral flux highlights energy jumps (drum hits, note attacks) into a per-frame novelty curve.
- Comb-filter search — tempos from 40 to 240 BPM are scored against the envelope; harmonically related candidates (120 vs 60) are disambiguated by octave weighting.
- Confidence scoring — the margin between best and runner-up tempo becomes the percentage you see; below 60% the UI suggests tapping.
- Tap override — clicking the tap pad 4+ times replaces the estimate with your interval median.
Half-time and double-time suspicions are labeled explicitly (may be 87 or 174) instead of guessing silently. Works on any audio the merge tool accepts, up to 100 MB.
Frequently asked questions
How accurate is the BPM detection?
FFmpeg's bpm filter detects tempo automatically and is generally accurate within ±1-2 BPM for music with a clear, steady beat. Very sparse, ambient or arrhythmic audio (spoken word, sound effects) may not return a reliable reading — the result will show 0 BPM in those cases.
What audio formats can I upload?
Any audio format FFmpeg can decode — MP3, WAV, FLAC, AAC, OGG, WMA, M4A and many more. The server handles formats your browser can't natively play, so you're never limited to browser-supported codecs.
What happens to my file?
The upload is deleted automatically within 30 minutes. The analysis runs entirely server-side and only the result summary is returned — the audio itself is never stored or shared.
Related tools
What Is a BPM Detector?
A BPM detector analyzes a piece of audio and tells you its tempo — the beats per minute — plus the file's technical specs: duration, sample rate, channel count, bitrate and codec. It is the pocket musicologist for DJs who need a track's tempo before mixing, producers checking whether a sample fits the grid, playlist curators organizing by tempo, and anyone managing a music library. The analysis runs on our servers using FFmpeg's bpm filter and ffprobe, and the report comes back as a neat summary — no output file is produced at all. You simply upload a file and read the numbers — no software, no setup, no guesswork.
What this tool can do
- 🥁 Detect the tempo in beats per minute
- ⏱️ Report the exact duration of the recording
- 📊 Show sample rate, channels, bitrate and codec
- 🧪 Deliver a clean analysis report — no media file generated
- 🎧 Accept any audio format, including ones the browser cannot decode
When you would use it
- Checking a track's tempo before mixing it into a DJ set
- Verifying a sample's BPM before placing it in a production
- Confirming a file's technical specs before uploading it anywhere
- Sorting a music collection by tempo for easier programming
Your audio is uploaded over an encrypted connection, analyzed on our servers, and automatically deleted within 30 minutes. Be aware that BPM detection is algorithmic: it is reliable for music with a steady beat, but speech, ambient sound and polyrhythmic pieces can produce an unclear reading, in which case the tool reports the tempo as unknown rather than guessing. For anything with a clear, regular beat, the number you get is a solid starting point.
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