Change audio volume
Boost a quiet recording, or level a track to a broadcast loudness target.
Your file
Drop a file here, or click to choose
It stays on this device. Nothing is sent anywhere.
Settings
Three ways to get louder
- Fixed gain multiplies everything by the same amount. Simple and predictable. Push it too far and the loudest peaks clip, which sounds like crackle.
- Normalise to -16 LUFS measures perceived loudness across the whole file and adjusts to the level podcast platforms expect. This is the right choice for spoken word.
- Peak normalise evens out the difference between loud and quiet passages, which helps recordings where someone drifts away from the microphone.
How much is a decibel
+6 dB is roughly twice as loud in signal terms. +3 dB is a noticeable lift. Above +12 dB on an already reasonable recording you are mostly amplifying room noise.
Why -16 LUFS is the number that keeps coming up
LUFS measures perceived loudness across a whole recording rather than the height of its tallest peak, which is why it correlates with how loud something actually sounds. Platforms adopted it because they need everything in a feed to arrive at a similar level. Podcast distributors expect around -16 LUFS for stereo, Spotify and YouTube normalise to roughly -14, and broadcast in Europe sits at -23.
The practical consequence is that a file delivered much louder than the target gets turned down anyway, and one delivered much quieter gets turned up along with all its noise. Normalising to -16 before you publish means the platform does nothing to your audio, which is the outcome you want. This is the setting to use for any spoken-word recording going anywhere public.
Gain, peaks and clipping
Fixed gain multiplies the whole signal. It is predictable, and it has a hard ceiling: once the loudest peaks reach the maximum a digital file can represent, further gain flattens their tops instead of raising them. That flattening is clipping, and it sounds like crackle or a harsh edge on louder passages. It cannot be undone afterwards, which is why it is worth being conservative and running the tool twice rather than reaching for +20 dB in one go.
Peak normalisation raises the file until its loudest moment sits just below the ceiling, at -1 dB. That guarantees no clipping and does not guarantee the result sounds louder, because a single stray peak, a door closing or a cough, will use up all the headroom and hold everything else down. When peak normalisation does very little, that is usually what happened.
Which to reach for
- An interview or podcast going out to listeners: normalise to -16 LUFS.
- A recording that is simply too quiet and needs a nudge: fixed gain, +6 dB, listen, repeat if needed.
- A file with one loud moment and a lot of quiet: peak normalise first to see where you stand, then decide.
- Music you are mastering properly: none of these. Use a real DAW; loudness on music is a mix decision, not a filter.
This works on video files too, not only audio ones. If a clip's sound is too quiet, run the video through here rather than extracting and rejoining.
Common questions
Boosting made it crackle. What now?
That is clipping. Use the -16 LUFS option instead, which raises loudness without pushing the peaks past the ceiling.
Can I remove background hiss?
Not with this tool. Noise reduction needs a different filter chain than what is exposed here.