Free tool · ITU-R BS.1770-4 · 100% in your browser
Online LUFS Meter & Key Finder
Professional loudness analysis and musical key detection in one pass. Integrated LUFS with true gating, oversampled True Peak, loudness range, short-term timeline, plus key, Camelot code and BPM. Nothing is uploaded — your audio never leaves this device.
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Private by design — analysis runs locally, nothing leaves your browser
Industry reality check
Streaming platforms normalize down, not up: a -8 LUFS master on Spotify simply gets turned down to -14. Yet most modern commercial masters in electronic music still land around -8 to -9 LUFS with true peaks at -0.5 to -1 dBTP, because loud masters keep their density and attitude even after normalization. Don't chase a number — chase translation. The right target depends on where your track will live: playlist, club, radio or sync.
Mastering reference
- Streaming: -14 to -16 LUFS integrated
- True Peak: ≤ -1.0 dBTP for lossy encoding
- Club / Beatport: -9 to -11 LUFS typical
- LRA: 4–8 LU for electronic music
Not where it should be? I can fix that.
How the LUFS meter works
Drop any audio file and the analyzer decodes it locally, applies the K-weighting filter chain defined by ITU-R BS.1770-4, and measures loudness in 400 ms gated blocks with both absolute (-70 LUFS) and relative (-10 LU) gating — the same method used by Spotify, Apple Music and broadcast standards. True Peak is estimated with 4× polyphase oversampling to catch inter-sample peaks that a simple sample-peak meter misses.
The key finder computes a chromagram of your track — the energy of the twelve pitch classes over time — and correlates it against Krumhansl-Schmuckler key profiles for all 24 major and minor keys. You get the detected key, its relative key, the Camelot wheel code for harmonic mixing, and an estimated BPM.
Streaming loudness targets
| Platform | Target | Normalization |
|---|---|---|
| Spotify | -14 LUFS | Turns louder tracks down |
| Apple Music | -16 LUFS | Sound Check on by default |
| YouTube | -14 LUFS | Turns down only |
| Amazon Music | -14 LUFS | Loudness normalization |
| Tidal | -14 LUFS | Album normalization |
| Deezer | -15 LUFS | Turns down only |
| Beatport / Club | No limit | -9 to -11 LUFS typical |
What is LUFS?
LUFS (Loudness Units relative to Full Scale) measures perceived loudness the way human hearing works, not just electrical signal level. Unlike peak or RMS meters, LUFS applies frequency weighting that mirrors the ear's sensitivity and gates out silence, which is why every major streaming platform uses it to normalize playback volume between tracks.
What is the Camelot wheel?
The Camelot wheel maps all 24 musical keys onto a clock face (1A–12A for minor, 1B–12B for major) so DJs and producers can mix harmonically: adjacent numbers and same-number A/B pairs blend smoothly. If your track reads 8A (A minor), it will mix cleanly with 7A, 9A and 8B.
Privacy
Everything runs in your browser using the Web Audio API. No upload, no server processing, no storage of your audio — close the tab and it's gone.