Find the BPM and the key
One file dropped, three answers: the tempo, the key (note and mode, to set an autotune) and the table of delay and reverb times locked to that tempo. Plus a metronome and a microphone tuner.
1
Analyze a track
Tempo, key, and a metronome click to confirm the tempo against the record itself.
Analyze a track
Tempo, key, and a metronome click to confirm the tempo against the record itself.
Drop a track here
or
WAV, MP3, M4A, FLAC — the file stays on your computer, nothing is sent.
Read from your own disk, never uploaded. If the click stays with the drums from start to finish, the tempo is right. Always slightly off? Nudge it in milliseconds.
2
The tempo, its delays and its reverbs
Filled in on its own after an analysis. Otherwise tap the tempo, or type the number: the table follows.
The tempo, its delays and its reverbs
Filled in on its own after an analysis. Otherwise tap the tempo, or type the number: the table follows.
Milliseconds, ready to type into the plugin.
3
Find a note, by voice or by instrument
Sing: the needle tells you which note you are closest to, and how far above or below you are.
Find a note, by voice or by instrument
Sing: the needle tells you which note you are closest to, and how far above or below you are.
This is what you will see: the note in large type, and the needle rising and falling as you go sharp or flat.
Sing or play a sustained note.
Nothing is recorded or transmitted. If a track was analyzed above, the tool tells you how many semitones to transpose the instrumental by to land on your voice.
How to read the result
The tempo is found by locating onsets — the instants where a sound starts — and then looking for the interval that comes back most regularly between them. That is reliable when the pulse is marked. When it is not, the tool says so instead of pretending.
What stays debatable is the counting level. Musically, half-time and double-time are often both defensible; the genre is what settles it. That is why the second plausible reading is always displayed, and why ÷2, ×2, ×⅔ and ×1.5 are one click away.
The key is read over the whole track: the tool weighs each pitch class, then compares that fingerprint to the twenty-four possible keys. When the fingerprint is weak — a mostly rhythmic track, a modulation halfway through, a production tuned away from standard pitch — the confidence badge drops and a warning appears. Check by ear before you rely on it.
A tool tells you what is there. It does not do the work.
Knowing the tempo and the key saves you time; it does not replace a mix. Alumire measures, and says what it measures — nothing is uploaded, nothing is sold, and no account is asked for.
Frequently asked
Is my file uploaded to your servers?
No. The track is decoded by your browser and analyzed on your own machine. Nothing is sent, nothing is kept — cut your connection once the page has loaded and the tool still works.
Why does the tempo sometimes come out half or double?
Because both readings are often musically correct. A track at 140 BPM with a snare every two beats can be counted at 70. The genre decides: rap usually sits around 80–95, house around 120–128, drum and bass around 170–175. That is why the second plausible reading is always shown — if that was the one you expected, it is one click away.
How is the key found?
The tool weighs how much of each of the twelve pitch classes the track contains, then compares that fingerprint to the twenty-four possible keys. A semitone error happens on productions tuned to something other than standard pitch — check by ear before you set an autotune on it. When the fingerprint is weak, the tool says so instead of pretending.
The metronome click does not fall exactly on the beat.
Two causes escape the analysis and stack up: the encoder padding an MP3 carries, which the decoder and the player do not always treat the same way, and the latency of your audio output (headphones, Bluetooth). Neither can be measured from a web page — hence the millisecond offset control, kept from one session to the next like in any DAW.
What are the delay and reverb figures for?
They are plain arithmetic on the tempo, in milliseconds, ready to be typed into a plugin: straight, dotted and triplet values from whole note down to 1/32, plus a pre-delay and two reverb tails that either die before the next beat or spill over it. You can also type a tempo by hand, or tap it — no file needed.
Which formats can I drop?
WAV, MP3, M4A and FLAC are safe everywhere. Anything else depends on what your browser can decode; if it cannot, the tool says so rather than returning a wrong number.