No upload, 100% local, no account

Audio volume

Boost or reduce the volume by a dB gain, or normalize to a consistent loudness. Everything runs in your browser, your file never leaves your device.

How Audio volume works

Audio volume lets you raise or lower a track by a precise number of decibels, or normalize it so its perceived loudness matches the EBU R128 broadcast standard. Use gain mode to boost a too-quiet voice memo, reduce a clipping recording, or match the levels of two files before merging them. Use normalize when you want several tracks in a playlist or podcast to sound roughly equally loud without manually tweaking each one.

Both modes run through ffmpeg compiled to WebAssembly. Gain applies the volume filter for a straight dB shift; normalize applies the loudnorm filter in a single pass targeting the EBU R128 integrated loudness target. Everything runs on your own device inside the browser tab; the audio file is never uploaded. No account, no watermark.

Written by Bastien Sulyan

How to use Audio volume, step by step

  1. Drop or select your audio file (MP3, WAV, M4A, AAC, OGG, FLAC).
  2. Choose the mode: Gain (manual dB shift) or Normalize (EBU R128).
  3. For Gain: set the number of decibels to add or subtract.
  4. Click Adjust Volume. ffmpeg processes the file locally in the browser tab.
  5. When complete, click Download to save the adjusted file.

Common use cases

  • Boosting a quiet voice recording by +6 dB or +12 dB before sharing it as a podcast.
  • Reducing an overdriven instrument track by a few dB to remove clipping artifacts.
  • Normalizing a batch of lecture recordings so they all play back at a consistent level.
  • Matching the volume of a background music bed to a narration track before merging them.

Frequently asked questions

Does my audio file get uploaded to adjust the volume?

No. ffmpeg compiled to WebAssembly adjusts the volume entirely in your browser tab. Your file is read into memory on your device, processed there with the volume filter (dB gain) or loudnorm (EBU R128 normalization), and the result is offered as a local download. Nothing is transmitted to Sunasty or any third party. Open your browser DevTools, switch to the Network tab, and trigger the volume change: you will see no outbound request carrying your audio.

What is the difference between dB gain and normalize?

Gain applies a fixed change you specify, in decibels. Every 6 dB roughly doubles the perceived loudness; +6 dB makes it about twice as loud, -6 dB makes it about half as loud. Normalize runs the ffmpeg loudnorm filter in a single-pass analysis and then adjusts the file to target the EBU R128 integrated loudness standard (-23 LUFS by convention). The result is an approximate normalization, not the precise two-pass measurement broadcasters use, but good enough to even out a set of files so they play at similar perceived levels.

Will boosting the volume cause distortion?

It can, yes. If your file is already loud and you add a large positive gain, the peaks may exceed 0 dBFS and clip, producing audible distortion. To avoid this, use the Normalize option instead of a large positive gain: loudnorm targets a moderate integrated loudness and keeps peaks under control. If you need both loudness and true-peak control, process with an audio editor that offers multi-pass loudnorm or limiting.

Does volume adjustment change my audio format?

The output uses the same container and codec as the input. An MP3 in is an MP3 out; a WAV stays a WAV. There is one re-encode pass for the volume change, but the format and sample rate are preserved.

What is EBU R128, and when should I use it?

EBU R128 is the European Broadcasting Union standard for loudness normalization. It measures integrated loudness in LUFS (Loudness Units relative to Full Scale) rather than peak dB. Use it when you want your audio to comply with broadcast or streaming platform requirements (YouTube, Spotify, and podcasting apps all use similar targets), or when you want multiple tracks to sound equally loud regardless of their peak levels.

Does audio volume work offline?

Mostly. The volume and loudnorm filters always run on your device, your audio never leaves your machine. The one caveat is that the ffmpeg engine is a sizeable download fetched from this site the first time you run the tool; once that download and the page have both completed, you can disconnect from the internet and the tool will still complete the job.