Loudness Normalizer

About Loudness Normalizer

Audio with inconsistent volume — quiet in some sections, loud in others, or simply recorded at a level below what feels natural on playback — benefits from normalization rather than a flat volume boost, since normalization analyzes and evens out perceived loudness across the whole track rather than uniformly scaling everything by the same fixed amount.

This uses FFmpeg's loudnorm filter, which implements the EBU R128 loudness standard — the same measurement standard broadcasters and streaming platforms use to ensure consistent perceived loudness across different content. The target settings used (-16 LUFS integrated loudness, -1.5dB true peak) match the common target for podcasts and general streaming content.

Unlike a simple gain boost (multiplying every sample by the same factor), loudness normalization analyzes the audio's actual perceived loudness characteristics and adjusts accordingly — this generally produces a more natural, professional-sounding result for content with varying volume than manually picking a flat gain value would.

A real FFmpeg build compiled to WebAssembly performs the analysis and normalization entirely inside your browser, re-encoding the result as MP3 with the evened-out loudness applied.

How it works

1. Upload your audio file. The file loads into the browser-based FFmpeg engine.
2. Normalization runs automatically. Loudness is analyzed and evened out using the EBU R128 standard.
3. Download the normalized file. Consistent volume, re-encoded as MP3.