BPMKeyFinder.com is a free educational website providing a browser-based audio analysis tool and educational content about BPM detection, musical key detection, the Camelot Wheel, and harmonic mixing — built for DJs, music producers, remixers, songwriters, and anyone who needs to know the tempo and key of a track instantly and privately.
The site was created and is maintained by Charlotte Hayes, a music analysis technologist and DJ/production educator with expertise in audio analysis algorithms, BPM and key detection technology, harmonic mixing theory, and music production workflow.
Why This Site Exists
Two numbers define the harmonic and rhythmic foundation of every piece of music: BPM and key. Knowing them opens every decision that follows — which tracks can transition smoothly into each other, which sample fits the session without transposition, which vocal will sit over which instrumental without a key clash.
Most tools that provide this information ask you to trade your privacy to get it. Your audio file is uploaded to a remote server, processed elsewhere, and returned to you — raising legitimate questions about what happens to the file on the way. Others require account creation or limit the number of free analyses.
BPMKeyFinder.com was built on a different principle: your audio never leaves your device. The analysis runs entirely within your browser. You upload the file, the result appears, and the file is cleared from browser memory when you leave the page. No server ever sees your audio.
What the Tool Provides
The BPM Key Finder analyses uploaded audio files and returns three pieces of information in a single result:
BPM (tempo). The tool detects the rhythmic pulse of the track using onset detection and beat tracking algorithms. For music with a clear rhythmic structure, accuracy is typically within ±1 BPM. Supported formats include MP3, WAV, FLAC, AAC, and OGG.
Musical key. The tool analyses the pitch class content of the track using a chromagram — a 12-element profile of the energy present at each of the twelve pitch classes — and matches it against established key templates to identify the root note and mode (major or minor). Key detection accuracy is typically above 80% on popular music genres. Results should be verified by ear for critical professional use.
Camelot Wheel notation. The detected key is automatically converted to its Camelot Wheel position — the DJ standard for harmonic mixing, used in Rekordbox, Traktor, and Serato. Every key is assigned a number (1–12) and a letter (A for minor, B for major). Keys with the same number, adjacent numbers, or the same number with opposite letters are harmonically compatible and will blend naturally in transitions.
What the Site Covers
Beyond the tool, BPMKeyFinder.com provides educational content in four areas:
Audio analysis and algorithm explanations. How BPM detection and key detection work at a signal processing level — onset detection, beat tracking, chromagram analysis, and key profile matching — with honest documentation of accuracy and limitations for different music types.
The Camelot Wheel and harmonic mixing. How the Camelot system works, the music theory behind harmonic compatibility, how different key transitions create different emotional effects, and how to use the wheel to plan sets and transitions.
Music production and DJ workflow. How BPM and key data are used in professional workflows — DJ set preparation, sample library management, mashup construction, DAW production with samples and loops, and vocal matching.
Music theory supporting BPM and key understanding. Intervals, major and minor tonality, the circle of fifths, relative major and minor keys, and the music theory concepts that make harmonic mixing work — explained for musicians, producers, and DJs who want to understand the system rather than just follow its rules.
Who This Site Is For
BPMKeyFinder.com is built for:
- DJs preparing sets who need BPM and Camelot notation for every track before mixing
- Music producers working with samples, loops, and vocals who need key and tempo data before building a session
- Remixers needing the original track’s key and BPM before starting a new version
- Songwriters wanting to match a new idea to the key or tempo of a reference track
- Music educators and students exploring how audio analysis and music theory relate
- Library managers and curators tagging collections with BPM and key metadata
- Anyone who wants to know the key and tempo of a song without uploading their files to an external server
Privacy by Design
Every audio file uploaded to BPMKeyFinder.com is processed locally in your browser using the Web Audio API. The file never travels over the internet to any server. When the analysis is complete and you close or navigate away, the decoded audio data is cleared from browser memory.
This means: your unreleased productions, your exclusive DJ tracks, your personal recordings — none of them are ever seen by any server, stored anywhere, or accessible to anyone other than you. Full technical details are in the Data Security page.
Research and Editorial Standards
All content on BPMKeyFinder.com is held to a consistent standard: algorithm descriptions are grounded in established signal processing science, accuracy claims reflect documented performance for the relevant music types, and limitations are disclosed clearly. The full research and editorial process is in the Editorial Guidelines page.
Get in Touch
Questions, corrections, and feedback are welcome. Contact us via the Contact page. All messages are reviewed personally by Charlotte Hayes.
BPMKeyFinder.com is an independent educational website. It is not affiliated with any DJ software company, music streaming platform, or audio hardware manufacturer.
Founded and maintained by Charlotte Hayes — music analysis technologist and DJ/production educator.
Last updated: June 2026.