Free BPM finder

How a BPM detector finds the tempo

BPM means beats per minute: how many steady pulses fit in sixty seconds. A song has no label that says so, so a BPM detector, also called a tempo finder or tempo detector, has to listen for it. First it turns the audio into a curve that rises every time something new starts, a drum hit, a plucked note, a chord change. Music people call this an onset curve.

Then it looks for the spacing that repeats. If the curve has peaks every half second, the tempo is 120 BPM. Our finder tests every tempo between 50 and 250 BPM against the whole song, not just a short excerpt, and refines the winner to a few hundredths of a BPM. That is why a steady track can come out as 127.96 and a loop made in a DAW as 128.

The method works best on music with drums or a clear rhythm. A solo piano ballad, a drone or a field recording has no steady pulse, and any BPM finder will struggle with it. When that happens we tell you the confidence is low instead of guessing out loud.

Half time and double time: why a song can be 70 or 140

Every tempo has cousins. A song at 140 BPM with the snare on beats two and four feels just as natural counted at 70 BPM. Neither answer is wrong, they are two ways to count the same pulse. Trap, drum and bass, dubstep and a lot of hip hop live in this gap, and so do slow ballads with busy hi-hats.

A BPM finder cannot know how you count, so we show the number we measured and put the half and double next to it. Pick the one that matches the way you write, DJ or dance to the song. The table, the delay times and the click all follow your choice.

As a rule of thumb, most dance music is counted between 120 and 150, hip hop between 70 and 100, and drum and bass at about 170 to 175. If your result lands outside the range you expect, try the other option first.

Check the BPM by ear with a click

A number on a screen is only useful if it is right, and the fastest test is your ear. Press play with a click and we lay a metronome over the song at the BPM we found, louder on every fourth beat. If the click rides on the kick, you are done. If it drifts, the tempo moves in the song or the number is off.

If the click sits halfway between the beats, the tempo is right and the grid is shifted. One button moves the click by half a beat. If it feels twice as busy or half as busy as the song, use the double or half option.

This takes ten seconds and saves you from the classic mistake of tagging a whole sample library with a wrong tempo.

BPM for DJs, producers, drummers and teachers

DJs need the tempo of every track before a set. Drop all the tracks of a crate, download the table as a CSV for your sheet and sort it there, and read the key of each song next to its BPM so that you can mix in key too.

Producers use the BPM of a sample to set the project tempo, to stretch a loop to the grid, or to find loops that fit. The table gives you the tempo, the key and the length of each file in one pass.

Drummers and band leaders use it to learn the tempo of a song they have to cover and to set the click for rehearsal. Teachers use it to prepare practice tracks at the right speed. For a tempo you hear but do not have as a file, use the tap tempo tool instead.

The AI beat tracker for a precise beat grid

The steady grid is perfect for songs made on a computer. A band that plays live speeds up and slows down, and a single BPM cannot follow that. For those songs there is an optional AI beat tracker. It is Beat This! small, a neural network from researchers at Johannes Kepler University Linz, published at ISMIR 2024 under the MIT license, in an ONNX export by danigb.

Press the AI button and your browser downloads the model once, about 10.8 MB, and keeps it. The network listens to the whole song and marks every beat and the first beat of every bar. You get the tempo it hears, the time signature, and a click that follows the real beats instead of a straight grid. Your song is never uploaded, the network runs on your device.

It is optional because it takes longer than the plain analysis and because it is no magic: on a song with no clear beat it will find none, and we say so.

Tips for a better reading

Use the full song, or at least a section with the drums in. An intro of pads and a long fade are hard to read and can pull the result off. Short loops work too: a clean loop whose length is a whole number of beats is confirmed by its own duration.

Prefer the original file to a heavily compressed copy, and avoid a version with a long silence at the start. If a track has a tempo change, we show the main tempo and tell you that the tempo moves.

If the confidence is low, tap the beat yourself on the tap tempo page, then compare. Two methods that agree are better than one.

A BPM finder that never uploads your music

Most online BPM tools send your file to a server and wait for an answer. That is slow for a large WAV and a bad idea for an unreleased demo. Here the analysis runs in a worker inside your browser. The only extra download is the optional AI model and the engine that runs it.

We only count anonymous usage, that a tool was used, the file type and the length in minutes. Never the file, its name or its content. It is free, it has no sign-up and no daily limit. It is a beta, so a song will sometimes come out wrong, and that is what the click check is for.