How to use
- Choose one or more audio files. The table shows each file's loudness (LUFS) and peak.
- Choose Normalize loudness and a target, or Adjust volume and drag the gain.
- Pick a format and click the button. Several files download as a ZIP.
Options explained
- LUFS
- Integrated loudness measured per ITU-R BS.1770, closer to what ears hear than peak or average level. Streaming services mostly use −14 LUFS, podcasts −16 and broadcast −23 (EBU R128).
- Peak limit
- After normalizing, peaks stay at or below −1 dBFS. If reaching the target would push a quiet file past that, it is only raised up to the limit.
Decibels and gain
A change of dB decibels multiplies the sample values by 10^(dB ÷ 20). A few useful points:
| Change | Multiplier |
|---|---|
| −6 dB | 0.50 |
| −3 dB | 0.71 |
| +3 dB | 1.41 |
| +6 dB | 2.00 |
| +10 dB | 3.16 |
| +20 dB | 10.0 |
When you normalize, the tool works out the gain as the target minus the measured loudness. A file measured at −20 LUFS needs +6 dB to reach −14 LUFS. Its peaks must be at or below −7 dBFS beforehand, because after the gain they must stay at or below −1 dBFS. If they are higher, the gain is reduced until the peak sits at −1 dBFS.
Frequently asked questions
Why didn't my file reach the target loudness?
It has loud moments (high peaks), and raising it further would clip, so the peak limit stopped it. Getting louder needs a compressor or limiter to control dynamics.
Does it reduce quality?
Not with WAV. M4A re-compresses once at 192 kbps AAC.
Are my files uploaded?
No. Everything happens in your browser.
Privacy
This tool runs entirely in your browser. Your files and text are processed on your device and are never uploaded to our servers.