LUFS stands for Loudness Units relative to Full Scale. It measures perceived loudness of audio over time, using a K-weighting filter that matches how human hearing works. Streaming platforms use LUFS targets to normalize all music to a consistent volume.

Is my audio uploaded to a server?

No. LoudFix processes all audio entirely in your browser using WebAssembly and the Web Audio API. Your files never leave your device.

What audio formats does LoudFix support?

LoudFix supports WAV, MP3, FLAC, AAC, OGG, OPUS, and AIFF as input formats. Output formats depend on the platform preset selected.

What LUFS target does Spotify use?

Spotify normalizes audio to −14 LUFS integrated loudness with a true peak limit of −1 dBTP. Tracks louder than this will be turned down; tracks quieter may be turned up.

What is true peak and why does it matter?

True peak measures the actual peak level of the reconstructed analog waveform, including intersample peaks that occur between digital samples. Streaming platforms cap true peak at −1 dBTP to prevent distortion during decoding.

Does normalizing audio affect quality?

LoudFix applies a linear gain adjustment only — it does not compress or limit the audio. This preserves 100% of your dynamic range. The only quality impact is from re-encoding to a lossy format (MP3, AAC) if you choose one.

LoudFix — Loudness Normalization for Streaming

LoudFix