Mastering in the browser.
Load a file, pick a profile, master it, compare A/B, save as WAV or MP3. Nothing is uploaded – everything runs on your own computer, no sign-up needed.
1 · File
WAV, MP3, M4A/AAC, FLAC and OGG – depending on your browser.
2 · Profile & target
Spotify, Apple Music and YouTube normalise everything to around −14 LUFS. Mastering louder gains no volume there – only less dynamics.
What the tool does – and what it doesn’t
It measures integrated loudness to ITU-R BS.1770 and true peak with 4× oversampling, tames typical artefacts of AI generators (sibilance between 5 and 9 kHz, rumble below 30 Hz), shapes the sound with a genre profile and brings the song to the chosen loudness with a look-ahead limiter. It does not replace a mastering engineer and cannot fix a bad mix. It does reliably deliver what distributors and streaming services expect. The guide Understanding loudness explains how to read the numbers.