Find the tempo of any song in seconds. Open an MP3, WAV or M4A file, or let this free BPM detector listen through your microphone while the music plays. It shows the BPM to one decimal, how sure it is, the half-time and double-time values and a beat grid you can play with a click track, so you can check the result by ear.
BPM Detector
Tempo of any song from a file or the microphone. Nothing is uploaded.
Confidence: –
Nothing is uploaded: the audio is analysed in your browser.
Violet lines are the beats (bar numbers on beat 1). Click the waveform to jump.
Half time or double time?
Tap to verify
Tempo over time
DJ and producer numbers
Related Tools
- Tempo Tapper
Tap along to any song to measure its BPM by hand.
- Online Metronome
Practise at the tempo you just found.
- Song Key Finder
Get the key and Camelot code to go with the BPM.
- Pitch Shifter
Change the tempo or the key of a song file.
- Spectrogram Viewer
See the drums and every other sound in a track.
- Chord Progression Finder
Find the chords of a song from audio.
How to Detect the BPM of a Song
- Add the music. Choose a song or drop it on the box (MP3, WAV, M4A, OGG, FLAC or the sound of an MP4 video, up to 150 MB and 15 minutes). No file? Press Listen with the microphone and play the song from a speaker or another phone for 10, 20 or 30 seconds.
- Read the tempo. The display shows the BPM with one decimal (for example 127.9), the rounded value (128), the tempo marking and a 10-step confidence meter. In microphone mode a live value appears after about 5 seconds.
- Check it by ear. Press Play. The song plays with a click on every detected beat, the beat light flashes and the violet grid lines scroll past the waveform. If the clicks sit on the kick and snare, the BPM is right.
- Use it. Switch to half or double time if the song feels that way, copy the result, or open the tempo straight in the metronome.
What the BPM Analyzer Shows
| Result | What it tells you |
|---|---|
| BPM + rounded BPM | The average tempo to 0.1 BPM, and the whole number most apps and DJ software use |
| Confidence | High, medium or low, from how regular and how clear the beats are. Speech, ambient music and noise show “No clear beat” instead of a made-up number |
| Half time / double time | The two related tempos, one tap away, for songs that can be counted either way |
| Beat grid and click track | Every detected beat on a scrolling waveform, bar numbers on beat 1, a flashing beat light and optional clicks |
| Tempo over time | A line under the waveform. It shows whether the tempo is steady, drifts like a live band, or changes (for example 100 → 120 BPM) |
| DJ and producer numbers | Pitch-fader range (±6 %), milliseconds per beat, bar length and delay times |
BPM Test: Check the Result by Tapping Along
No tempo detector is right for every song, so this one lets you test its answer. Press Play and tap the big TAP button (or the Space bar) on every beat. After four taps it compares your tempo with the detected one: a match within 3 % gets a green tick, and if you tap at exactly half or double speed it tells you and offers the other value. While the song plays it also shows whether your taps land before or after the grid, so you can see that the beats are in the right place, not only the right speed.
Quick check: BPM = 60 ÷ the time between two beats in seconds. A beat every 0.5 s is 120 BPM; every 0.47 s is about 128 BPM. For a manual count without any audio file, the tempo tapper in Related Tools does the same by hand.
Half Time, Double Time and Tempo Changes
The most common disagreement about a song’s BPM is not a small error but a factor of two. A trap beat at 140 BPM feels like 70, and a slow soul ballad at 70 can be counted at 140 when the hi-hats move in eighth notes. The detector looks at which beats carry the kick and snare and which carry only hi-hats, and prefers the tempo most listeners tap. The other two values stay next to the result, so you can switch with one press and the grid and clicks follow.
Songs recorded without a click track drift a little, and some change tempo on purpose. The tempo-over-time line shows both: a flat line for programmed music, a gently wavy one for a live band, and a step when the tempo really changes. Each section gets its own BPM.
BPM Ranges by Genre
| BPM | Tempo marking | Typical music |
|---|---|---|
| 60–76 | Adagio | Ballads, R&B, lo-fi |
| 76–108 | Andante | Hip-hop (85–100), reggaeton (90–100) |
| 108–120 | Moderato | Pop, funk, disco |
| 120–156 | Allegro | House (120–130), techno and trance (125–145), dubstep (140) |
| 156–200 | Vivace to Presto | Drum & bass (160–180), punk |
BPM for DJs and Producers
Beat-matching works when two tracks share a tempo, or when one is half or double the other. A standard ±6 % pitch fader takes a 128 BPM track anywhere from 120.3 to 135.7 BPM, and the tool lists that range for every result. Producers get the beat length in milliseconds (60,000 ÷ BPM) with the eighth, dotted-eighth and sixteenth delay times, ready for a delay or reverb pre-delay. To speed a song up or slow it down without changing its pitch, open it in the pitch shifter; to practise at the new tempo, press Open in metronome and the online metronome starts at the same BPM.
How the BPM Detection Works
The detector decodes the audio in your browser and builds an onset curve: a Fourier transform splits each 11-millisecond slice into four frequency bands (kick, bass and snare, mids, hi-hats) and measures how fast the energy rises in each. Autocorrelation of that curve finds the repeating beat period; a comb of beat positions checks the half-beats and third-beats to choose between half time and double time; and a dynamic-programming beat tracker places each beat, following the tempo if it drifts or changes. The final BPM is a straight-line fit through all the beats of a section, which is why it can show a decimal. More on the frequency side of the same maths in how to read a spectrogram.
We tested it on 48 synthesised tracks: click tracks from 60 to 174 BPM, drum loops in rock, house, hip-hop and shuffle styles from 66 to 178 BPM with added noise, a live-style track with drift and timing jitter, a pop mix with quiet drums, a waltz, a soft 72 BPM ballad without drums and a track that changes from 100 to 120 BPM. It found the tempo within 1 BPM, in the right octave, in 44 of 45 steady tracks (98 %); the one miss was a house loop at 78 BPM read as 156. The tempo change was split into its two sections, and noise and silence gave “No clear beat”. How we test our tools is explained on the methodology page.
Tips for an Accurate Result
- Use at least 20–30 seconds with drums or a clear pulse; the whole song is best.
- In microphone mode, play the music loud enough and keep the phone close to the speaker. Nothing is recorded to any server: the sound stays in your browser (see data security).
- If the confidence is low, check the half or double value by tapping along.
- Free-tempo music (rubato piano, ambient pads) has no single BPM; the tempo line shows how it moves.
Frequently Asked Questions
What BPM is this song?
Open the song file or let the tool listen to it through the microphone: the BPM appears in a few seconds. Play it back with the click track to be sure.
Is my song uploaded?
No. The file is decoded and analysed on your device, and microphone sound is analysed live. The heard audio stays in the page only so you can replay it with the beat grid.
Can I check the BPM of a song on YouTube or Spotify?
Yes. Play it on one device and press Listen with the microphone on another, or on the same laptop near its speakers.
Why does it say half the BPM I expected?
Many songs can be counted at two speeds. Press Double time, or tap along to see which one you feel.
Can it find the key and the pitch too?
This page measures tempo only. For the key, use the song key finder; for the note someone is singing or playing, use the pitch detector or the note finder.
What is a normal BPM for a song?
Most pop and dance music sits between 90 and 130 BPM; the genre table above lists the usual ranges.