Inspect audio

BPM Finder & Tap Tempo

Estimate a song's tempo from a local audio file, compare half and double BPM, or tap the beat with a button or the space bar.

Runs locally in your browser

Local workspace

Process a local file

No media upload

Choose a file Select from your device or drop it here.

On-device

Your selected media stays on this device. AudioFetcher loads its processing engine, reads the file in browser memory, and creates the result locally.

Temporary

Refresh or close the tab and the selected file and generated result leave browser memory.

Honest limits

Steady beats work best. Speech, ambient music, tempo changes and weak percussion can produce an uncertain result. Files up to 64 MB; the detector uses at most 60 seconds near the middle.

How to use BPM Finder & Tap Tempo

1
Choose a local audio file up to 64 MB, or use the tap button without selecting a file.
2
Select Find BPM. The detector analyses up to 60 seconds near the middle of the recording.
3
Read the estimate and confidence hint. Listen for whether the half or double alternative matches the musical pulse.
4
Tap steadily on the button or press Space away from form fields to confirm the tempo. Reset when you want to start again.

What this tool changes

Estimate a song's tempo from a local audio file, compare half and double BPM, or tap the beat with a button or the space bar.

Steady beats work best. Speech, ambient music, tempo changes and weak percussion can produce an uncertain result. Files up to 64 MB; the detector uses at most 60 seconds near the middle.

What BPM means and when it helps

BPM means beats per minute: a count of the recurring pulse you follow through a piece of music. At 120 BPM, one beat arrives every half second. Tempo helps DJs line up tracks, musicians choose a metronome setting and listeners organise a running or workout playlist. It can also help estimate how long a repeated phrase will take when preparing a practice exercise.

The strongest sound is not always the beat. A singer can enter between beats, and a drum pattern can repeat over several beats. Decide which pulse you would count while listening. Running cadence is a separate measure: you might take one step on each beat or use a different relationship. A detector's number is useful for sorting and exploration, but it should not replace your own sense of the music or dictate a training pace.

How the local song BPM detector works

The detector reads the audio on your device and uses a section of up to one minute around the centre of the track. That avoids many quiet intros and outros, although it can still land on a breakdown or a section with a changing rhythm. A short recording uses the available audio instead. The original file stays unchanged, and the result includes the actual analysed time range so you know what the estimate covers.

Short frequency windows are compared to build an onset-strength envelope: a sequence highlighting increases in energy. The tool compares that sequence with delayed copies of itself to find recurring intervals. It searches a bounded tempo range and reports an estimate rounded to one decimal place. Stronger repetition produces a stronger confidence hint. This hint describes consistency in the sampled audio; it is not a percentage guarantee that the musical interpretation is right.

Why half and double tempo both appear

A regular pattern often supports more than one sensible count. A song heard as 128 BPM may also feel like 64 BPM if you count a broader pulse, or 256 BPM if you count subdivisions. The detector shows these alternatives because autocorrelation finds repeating events, not the notation or intention of the composer. A snare repeating on alternate beats can make the slower interpretation especially prominent.

Listen to a full phrase and count along rather than accepting the largest number. Check whether a metronome would land comfortably on the main pulse. A dense pattern does not necessarily mean the track is fast; there may be several notes inside each beat. Tempo changes, swing and irregular metre can spread or weaken the repeating peaks. For live recordings, the most useful answer may be an approximate range rather than a single decimal number.

Tap tempo tips for a better estimate

Listen first, then tap the same pulse several times without trying to chase every drum hit. The tool averages the last eight intervals, so the first two taps give an early number and additional taps make accidental timing errors less influential. Use a mouse, a touch screen or the space bar. Space does not trigger the page shortcut while you are editing a form field or activating another button.

If you lose the beat, use Reset instead of mixing two different tapping patterns. A pause longer than three seconds starts a fresh sequence automatically, and very rapid duplicate taps are ignored. Human tapping is approximate, so a reading such as 119.7 is usually better interpreted as around 120 BPM. Try a second sequence and compare it with the automatic result. You can tap tempo without choosing a file, which is useful for live music or a song playing on another device.

Genre ranges are only a starting point

Genre names describe style rather than a strict tempo boundary. House is commonly associated with a steady dance pulse around 120–130 BPM, while much drum and bass is counted around 160–180 BPM. Individual tracks can sit outside those ranges, use half-time rhythms or change tempo. Rock, pop, hip-hop and classical music span too many tempos for a narrow number to be a reliable classification.

Use a genre expectation as a listening prompt rather than forcing the detector to match it. If a house track appears around 62 BPM, its double-time alternative may make sense. If a recording has no steady pulse, tap a section with a clearer rhythm or use a metronome in a music app. A desktop audio editor can help mark beat positions when you need precision for editing. The audio speed changer is a separate tool for making a practice copy after you decide the starting tempo.