OneTaskBy Tim King · Updated
Audio Normalizer
Normalise Audio to a Peak dBFS or LUFS Target, Such as -14 for Streaming
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How the Audio Normalizer works
This audio normalizer sets peak or loudness to a target. Drop a file in and the page measures its peak level and integrated loudness. Choose Peak to raise or lower the file so its loudest sample hits your target, or LUFS to match a loudness standard such as -14 for Spotify or -16 for podcasts. The stats show the gain that will be applied and the resulting peak. Nothing is uploaded.
Audio normalizer: what it does and why
Normalising means working out how far a file is from a target level and applying exactly that much gain. The whole file moves together, so the dynamics are untouched; it just ends up at the level you asked for. The difference between the two modes is what "level" means.
Peak normalisation looks for the single loudest sample and moves it to the target, typically -1 dBFS to leave a little safety margin below the digital ceiling. It guarantees the file will not clip, but it says nothing about how loud it sounds: a recording with one sharp click and a quiet body will barely move, while a dense, compressed track will end up much louder to the ear. It is the right choice for preparing files for further editing, where headroom matters more than perceived loudness.
LUFS normalisation measures loudness the way ears hear it, using the ITU-R BS.1770 algorithm — a filter that mimics the ear's frequency response, then a gated average of the energy over the whole file. Streaming platforms and broadcasters all use it. Spotify, YouTube and Amazon aim around -14 LUFS; Apple Podcasts recommends -16; broadcast in Europe is -23. Setting the target here means the file will sit at the same subjective volume as everything else at that target. The stats panel shows the measured integrated loudness, the loudness range and the true peak before anything is changed.
When LUFS pushes past the ceiling. A quiet file normalised up to -14 LUFS may need more gain than its peaks allow. The page tells you when the resulting peak would exceed 0 dBFS and hard-clips at the ceiling rather than silently distorting elsewhere; if you see that warning, either accept a lower target or run the file through the Audio Volume Changer with clipping protection first, which soft-limits the peaks and makes room.
Measurement takes a moment. The loudness calculation runs over every sample of the file when it loads, so a long recording shows a short pause before the stats appear. The gain figures in the stats update instantly as you change targets once the measurement is done.
Output. WAV 24-bit preserves the most detail after a gain change; MP3 at 192 kbps or above is fine for delivery. Channel count and sample rate are preserved.
FAQ
What LUFS target should I use?
-14 for music going to Spotify, YouTube or Amazon; -16 for podcasts on Apple and most other platforms; -23 for European broadcast; -24 for US broadcast. If you are unsure, -16 is a safe middle ground for speech and -14 for music.
Why does the file still sound quiet after peak normalising?
Because peak normalisation only cares about the loudest sample. One short spike near the ceiling stops the rest of the file from being lifted. Switch to LUFS mode, which targets average loudness, and let the page tell you if the peaks then need limiting.
Does normalising change the sound quality?
No. It applies one constant gain to every sample, which is the gentlest possible operation. The only quality change comes from the export format you choose, so pick WAV if you plan to edit further.
Can I normalise several files to the same level?
One at a time: drop each file, keep the same target, export. Because the target is absolute rather than relative, every file you process will come out at the same loudness, which is exactly what you want for an album or a series of episodes.
Does the file leave my computer?
No. Decoding, measurement and gain are done by this tab using the Web Audio API, and the result is saved directly from the browser to your own device.
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