How do I find the BPM and key of a song?

Drop the audio file onto this page. It decodes the file in your browser, measures the spacing between rhythmic onsets to estimate tempo in beats per minute, and compares the distribution of pitches against major and minor key profiles to estimate the key. No account and no upload is needed, and you can analyze up to 25 files at once.

Is my music uploaded anywhere?

No. Analysis runs entirely in this browser tab using the Web Audio API. Your file is never sent to a server, never written to storage, and disappears when you close or reload the page — which is what makes it safe for unreleased tracks, demos, stems, samples and client work.

Why does the tempo look half or double what I expected?

Tempo detection identifies a repeating pulse, and a pulse at 75 BPM is mathematically also a pulse at 150 BPM. Both readings are shown when they are plausible — pick the one you would tap your foot to. Tracks with a strong backbeat, a halftime drum pattern or a heavy triplet feel are the most common cause.

Why is the detected key sometimes the relative minor?

A key estimate is based on which pitches appear most often, and relative majors and minors contain the same notes — C major and A minor are indistinguishable by pitch content alone. The relative key and the next most likely candidates are always shown, so check which one your root note and final chord sit on.

What is Camelot notation and how do I use it?

Camelot notation renames each of the 24 keys as a number from 1 to 12 plus a letter: A for minor, B for major. A minor becomes 8A and C major becomes 8B. Keys whose codes are adjacent share most of their notes, so mixing from 8A into 7A, 9A or 8B almost always sounds harmonically smooth. It is the standard shorthand in DJ software because it turns music theory into simple arithmetic.

Can I analyze several files at once?

Yes. Select or drop up to 25 files and they are analyzed one at a time so your device does not run out of memory. Results appear in a table with tempo, key, Camelot code and confidence, and you can export the whole batch as a CSV to drop into a spreadsheet or your library notes.

What file formats work?

Anything your browser can decode: WAV, MP3, FLAC, M4A, AAC, AIFF, OGG and Opus all work. Stems, loops and rough bounces are fine. Files up to 250 MB are accepted, and very short or free-tempo material may return no tempo at all, which is reported rather than guessed.

Treat both numbers as estimates with a stated confidence, not measurements. They are most reliable on material with an audible steady pulse and a clear tonal centre, and least reliable on ambient, rubato, spoken, modulating or heavily percussive-only audio. Confidence and alternative readings are shown so you can sanity-check a result rather than take it on trust.

Free tool

BPM & key finder

Drop a track, stem, sample or rough bounce and read its tempo, key and Camelot code — one file or a whole folder. Everything is decoded in your browser and never uploaded, the same analysis ANYANO runs on your own music when you prepare it for training.

Drop audio files to analyze

One song, beat or sample — or up to 25 at once. WAV, MP3, FLAC, M4A, AIFF, OGG and anything else your browser can decode.

Private by design. Your music is analyzed locally in your browser. It is not uploaded and it is not stored — which is what makes this safe for unreleased music, demos, stems, samples and client work.

Method

What the analyzer actually measures

Two separate measurements, run on the same decoded audio.

Tempo, from rhythmic onsets

The audio is reduced to an onset envelope — a curve that spikes wherever energy rises sharply, which is where hits land. The spacing that best repeats across that curve becomes the beat period, converted to beats per minute. Half and double readings are surfaced instead of hidden.

Key, from pitch distribution

Energy across roughly five octaves is folded into the twelve pitch classes to build a chroma profile, then matched against established major and minor key profiles. The closest match is the reported key, with its relative key and runners-up alongside it.

What happens to your file

Your fileDecoded in your tabEstimates on screenDiscarded

Harmonic mixing

How to read a Camelot code

Camelot notation is a way of renaming the 24 keys so that harmonic relationships become arithmetic. Each key gets a number from 1 to 12 and a letter: A for minor, B for major. A minor is 8A; C major, which shares the same notes, is 8B.

Arranged that way, keys next to each other on the wheel differ by a single note. So from 8A you can move to 7A, 9A or 8B and expect the transition to sit comfortably. Moving several steps at once, or jumping between distant numbers, is where clashes come from — which is exactly the problem the wheel was invented to make visible.

The same logic applies outside DJing. If you are layering a sample over your own track, picking a loop from a pack, or deciding which of your demos belong in the same body of work, adjacent Camelot codes are the ones that will need the least transposing.

Context

Why tempo and key matter before training

If you are only checking one track, tempo and key are practical facts: they tell you what will beatmatch, what you can layer, and what you have to transpose. If you are preparing a body of work, they become something else — a map of your own catalog.

ANYANO reads BPM and key for every file you add to Your Music, because a Sound trained on a consistent set of material learns a clearer identity than one trained on a scattered set. A group of tracks sitting in a narrow tempo range with related keys gives a model something coherent to learn from. Seeing those numbers across your own files is usually the moment it becomes obvious which material belongs together.

Nothing here requires an account. If you want the same reading applied across a whole catalog, kept private to you, and used to train a Sound of your own, that is what the studio is for.

FAQ

Frequently asked questions

Train your sound. Generate your song.

Your uploads stay private to your account. Confirm the rights, prepare your music, train your own Sound, then generate from it.

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