Key & BPM Detector
Find the key and BPM of any song or sample in seconds — free, in your browser, no signup
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The key & BPM detector finds the musical key and tempo of any song or sample in seconds. Upload an audio file and it reports the key, the relative major or minor, the Camelot code for harmonic mixing, the BPM, and a list of compatible keys — all free, in your browser, with no signup. Your audio is analyzed locally on your device and never leaves your computer.
How key and BPM detection works
Drop in an MP3, WAV, FLAC, or OGG file. The tool decodes the audio and measures how strongly each of the twelve pitch classes is present across the track, then matches that profile against Krumhansl-Schmuckler major and minor key templates to estimate the key. In parallel, it studies the rhythmic energy to estimate the tempo in BPM. Both results come back with a confidence score so you know how much to trust them, plus the Camelot code and compatible keys for mixing.
When producers, composers, and DJs use it
Knowing the key and tempo up front saves you from guessing — and from a track that fights itself harmonically. Common use cases:
- Harmonic mixing — read the key and Camelot code of two tracks so they blend in a DJ set or mashup instead of clashing.
- Key-matching a sample to your project — detect the key of a loop or one-shot, then pitch it to sit in the same key as the rest of your beat.
- DJ key compatibility — use the compatible-keys list to find tracks that mix smoothly with what is already playing.
- Sampling and remixing — find the original key and tempo of a record you are flipping so your new parts stay in the pocket.
Frequently asked questions
How do I find the key of a song?
Upload an audio file (MP3, WAV, FLAC, or OGG) and the detector analyzes its pitch content to estimate the musical key, the relative minor or major, and the Camelot code for harmonic mixing — usually in a few seconds. It also reports the BPM at the same time, so one upload gives you both the key and the tempo. Everything runs in your browser, free and with no signup.
How accurate is automatic key detection?
The detector uses Krumhansl-Schmuckler key profiles, the same approach behind professional key-finding software, and reports a confidence score with every result. It is most reliable on tonal material with clear harmony. Tracks that modulate between keys, sit on a single drone, or are heavily percussive can be ambiguous — the confidence score tells you when to trust the reading and when to double-check by ear.
What is the Camelot wheel and how do I use it?
The Camelot wheel maps every key to a number-and-letter code (for example, A minor is 8A) so you can mix harmonically without knowing music theory. Keys that share a number or sit next to each other on the wheel blend smoothly. This tool shows the Camelot code and a list of compatible keys for every result, and the dedicated Camelot Wheel tool lets you explore the full circle.
Can I find both the key and the BPM at once?
Yes. A single upload returns the musical key, the Camelot code, the tempo in BPM, and compatible keys — so you do not need a separate BPM finder. If you only need to tap out a tempo by ear, the BPM Tap Tempo tool is a faster fit for live or vinyl sources with no file to upload.
Do I need to install software or sign up?
No. The key and BPM detector runs entirely in your browser — there is no plugin, no download, and no account required. Your audio is analyzed locally on your device and is never uploaded to a server.
Related tools and pages
- BPM Tap Tempo — tap out the tempo by ear, no file needed
- Camelot Wheel — explore harmonically-compatible keys
- Free Online Mastering — master your finished track to a streaming-ready level, free and in your browser
- Describe & Find — search cleared samples by genre, key, and BPM
- Explore the Selekt catalog — filter by key, BPM, mood, and instrument
