Tools › Audio
Normalize audio loudness
Measure integrated loudness (LUFS), true peak and loudness range, then match Spotify, YouTube, Apple Music, podcast, audiobook (ACX) or broadcast EBU R128 targets. Free and private.
How it works
- Loudness is measured exactly as ITU-R BS.1770-4 and EBU R128 describe: K-weighting, 400 ms blocks and two-stage gating. True peak uses the 4× oversampling filter from the standard.
- The whole file is turned up or down by one fixed amount, so the dynamics of your mix stay as they are.
- If reaching the target would push peaks over the ceiling, a look-ahead true-peak limiter catches just those peaks. You can switch it off and stop at the ceiling instead.
Questions
What does -14 LUFS mean?
It’s the average loudness Spotify and YouTube play music at. Louder masters are turned down, so mastering hotter brings no advantage.
Is this the same number other meters show?
It should be within 0.1 LU of any BS.1770-4 meter. We check it against EBU reference signals and FFmpeg’s ebur128 filter.
What about audiobooks?
ACX measures RMS, not LUFS. The audiobook preset targets -20 dB RMS with peaks below -3.5 dB, which sits inside ACX’s -23 to -18 dB window.