AudioKit

Volume booster for audio files

Make quiet recordings, songs and voice notes louder without the crackle. See your file’s headroom, then boost with a limiter or normalise to a loudness standard.

  • Runs on your device
  • No upload
  • No sign-up
  • Free

Open a quiet recording, song or video

Stays on this device: nothing is uploaded. You can also drag a file here or paste it.

This makes the file itself louder, so it stays loud on every device and app. Just want your speakers louder right now? Check the volume in the app that’s playing, your system volume, and any per-site sound setting in the browser first.

Why “louder” has a ceiling

Every sample in a digital file is a number between −1 and +1. That boundary is 0 dBFS (decibels relative to full scale). The meter above shows your file’s peak, its loudest single sample. The gap between that peak and 0 dBFS is headroom: you can boost by that many decibels for free.

Past that point you have two options. Let peaks clip (bad), or use a limiter, which turns down just the few milliseconds around each peak. Speech and most pop tolerate 3–6 dB of limiting without anyone noticing. Push much harder and the sound starts to pump and flatten, which is the “loudness war” sound of many 2000s CDs.

If you’re matching levels across episodes or songs, loudness normalisation is better than peak-based boosting: two files with the same peak can sound very different in loudness. The LUFS measure in EBU R128 and ITU-R BS.1770 models how loud people perceive sound to be.

Matching several files? The audio normalizer opens straight into LUFS mode.

Questions people ask

How do I increase the volume of an MP3?

Open it above, choose “Boost by decibels”, set how much louder (+6 dB is a clear step up), keep the limiter on and export. The tool shows how much headroom your file has so you can see whether peaks will be squashed.

Why does my audio distort when I make it louder?

Digital audio has a hard ceiling at 0 dBFS. Push a peak past it and the top of the wave is cut flat, which you hear as crackle. A limiter prevents this by turning only those peaks down, very quickly, so the rest can get louder.

What is the difference between boosting and normalising?

Boosting adds a fixed number of decibels. Loudness normalisation measures how loud the whole file sounds (in LUFS, per the EBU R128 standard) and adjusts it to a target, such as −14 LUFS for Spotify and YouTube or −16 LUFS for podcasts. Use it to make several files equally loud.

How much louder is +6 dB?

+6 dB doubles the wave’s amplitude. Perceived loudness roughly doubles every +10 dB, so +6 dB sounds about 1.5× as loud.

How can I make an MP3 louder on my phone?

Open this page in your phone’s browser, tap Choose file, pick the MP3, keep +6 dB with the limiter on, and tap Export. Then tap Share or Download to save it.

Can I boost the volume of a video?

You can boost the soundtrack: open the video and export the louder audio. AudioKit doesn’t rewrite the video file itself.

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