How to make an audio file louder
- Drop an audio file into the box. The tool shows its waveform and current peak level.
- Move the Gain slider between -20 and +20 dB, or enter a target such as -1 dBFS and click Normalize.
- Leave Soft limiter on to prevent distortion when boosting, and watch the New peak and Clipping readouts.
- Press Preview to listen; slider changes apply live while it plays.
- Choose MP3 or WAV and click Export to download the louder or quieter file.
What you can do with Volume Booster & Normalizer
- Adjustable gain, ±20 dB
- Adjust in 0.1 dB steps. Every 6 dB roughly doubles or halves the signal level, and +10 dB sounds about twice as loud.
- One-click peak normalize
- Set a target peak between -30 and 0 dBFS and the tool calculates the exact gain needed to reach it.
- Soft limiter
- Rounds off peaks above about -2 dBFS instead of hard clipping, so you can push quiet audio louder without harsh distortion.
- Clipping counter
- With the limiter off, the tool counts exactly how many samples would clip at your chosen gain.
- Live preview
- Hear the gain and limiter while the file plays, and move the slider without restarting playback.
- Local processing
- Boosting and encoding happen in your browser, so private recordings, lectures and voicemails are never uploaded.
dBFS, headroom and peak vs loudness normalization
Digital audio is measured in dBFS, decibels relative to full scale, where 0 dBFS is the loudest value a file can store. If a file already peaks near 0 dBFS, adding gain pushes samples past that ceiling and they clip, which sounds like crackling distortion. That's why the tool shows the original peak first: a recording peaking at -12 dBFS has 11 dB of clean headroom before it reaches a -1 dBFS target. Normalizing to -1 dBFS rather than 0 leaves a small margin so MP3 encoding doesn't create overs.
Peak normalization makes the loudest moment hit a target; it doesn't make two files equally loud to the ear, because perceived loudness depends on the average level. A quiet voice memo with one loud cough won't get much louder from normalizing alone. In that case, raise the gain further and let the soft limiter tame the occasional peak. Streaming platforms such as Spotify and YouTube adjust playback toward roughly -14 LUFS; you can measure a file's LUFS with the Audio Spectrum Analyzer before and after boosting.
Frequently asked questions
How much louder can I make an MP3?
Up to +20 dB, which is about four times as loud to the ear. How far you can go without distortion depends on the file's headroom. With the soft limiter on, peaks are rounded off rather than clipped, but very high gain on dense music will still sound squashed.
Is my audio uploaded when I boost the volume?
No. The gain, limiter and MP3 encoding all run in your browser. The file stays on your device, which makes the volume booster suitable for private interviews, lectures, voicemails and unreleased music.
What is the difference between gain and normalize?
Gain changes the level by a fixed amount you choose. Normalize measures the file's current peak and sets the gain automatically so the loudest sample lands on your target, for example -1 dBFS. Both use the same processing; normalize just does the math for you.
Can I make audio quieter too?
Yes. Drag the gain below 0 dB, down to -20 dB, or normalize to a lower target such as -6 dBFS. The exported file is named with -quieter so you can tell it apart from the original, and louder files get -louder.
Can I increase the volume of a video?
This tool exports audio only. Extract the soundtrack with the Video to Audio tool, boost it here, and recombine it in a video editor. It can open the audio track of many MP4 files directly, but the result is always an MP3 or WAV file.