BPM finder for song files

BPM is beats per minute: how many times the steady pulse of a song falls in one minute, the beat you would tap your foot to. DJs match records by it, runners pick playlists by it, and producers need it to line a sample up with a session. This page works it out from the audio itself, so you need the song as a file.

The page finds the loudness jumps in the sound and the steady beat they line up with. It rounds the answer to a whole number and gives the tempo its traditional name, such as Andante or Allegro.

A worked example: you drop track.mp3 and the page shows 100 BPM, Andante, with the line “Also read as: 50 or 200”. Under it come the key, A minor, its Camelot code, 8A, and the relative key, C major, 8B, marked Likely. The BPM is the part to use if you only need the tempo; the rest is there for mixing.

If you have no file and only hear the song, use Tap tempo and tap along instead.

How to read the BPM

• The number is the pulse of the whole file, rounded to a whole BPM, with its tempo name underneath.
• The page folds every answer into 70 to 180 BPM. A slow ballad that the detector hears at 60 is shown as 120, and a very fast track is shown at half. The detector’s own number is in the results file, in the bpm_raw column.
• When the headline is between about 80 and 120 BPM, the page adds “Also read as” with the half and the double, because a slow song with busy drums and a fast one can have the same pulse. Outside that range it shows no alternatives, since the half or the double would be too slow or too fast to be useful.
• Pick the reading that matches how the song feels, or the one your DJ software or session expects.

More than one song

• Drop several files and the page analyses them one after another, with a card for each.
• Press the button on a card to copy its result as text, or save all of them as a file named bpm-key-results.csv.
• The results file lists the file name, the length, the BPM, the key, its Camelot code and whether the key was Likely or Unsure. It is made on your device and not sent anywhere.

What this page does not do

• It assumes one steady tempo. A song that speeds up, slows down or is played without a click can get a BPM that matches only part of it.
• It reads a file, not a link. A streaming-service or video link cannot be analysed, because the page never fetches anything for you.
• It refuses a clip shorter than 10 seconds, which is too short to find a tempo, and a file longer than 15 minutes. For a longer file, cut the part you want with Trim audio.
• A file with no steady beat, such as speech, a drone or a very quiet recording, gets no BPM. The key is still shown if it could be read.

The key and the Camelot code

Each result also names the key, with its relative major or minor and its Camelot code, which DJ software shows next to the BPM. A key marked Unsure is a guess to check against an instrument. For a page that starts from the key, see the BPM and key finder, and for all 24 codes see the Camelot wheel.