Adjust Audio Volume
Free online batch volume adjuster: upload multiple audio files and bring them all to the same loudness with peak normalization, or apply the same gain (-24 to +24 dB). Download one by one or as a ZIP — runs locally, no upload.
About this tool
Upload a whole batch of audio files at once and level them in one click: peak normalization brings every file to the same maximum loudness, or use the gain slider (-24 to +24 dB) to raise or lower all of them by the same amount. Download each result individually or grab everything as a ZIP. Everything runs locally in your browser.
How to use
- Click or drag to add one or more audio files
- Keep "Normalize all to the same peak" checked, or uncheck it and set a gain in dB
- Choose the output format and bitrate
- Click "Process all" and download the results individually or as a ZIP
FAQ
What is peak normalization?
The tool finds the loudest sample in the file and amplifies everything by exactly the amount needed to bring that peak to full level (0 dB). Quiet recordings become as loud as possible without clipping.
How does batch normalization work?
Each file is normalized independently to the same peak level (0 dB). Recordings from different sources end up at a consistent maximum loudness, which is the easiest way to even out a batch of files.
Why does too much gain cause distortion?
Digital audio has a hard ceiling at 0 dB. If amplification pushes the waveform past it, the tops get clipped off and you hear harsh distortion. If this happens, lower the gain or use normalization instead.
Are my audio files uploaded to a server?
No. All processing runs locally in your browser. Your files never leave your device.
Related tools
WAV to MP3
Convert WAV files to MP3 online for free. Everything runs locally in your browser — your files are never uploaded.
Compress Audio
Free online audio compressor that runs entirely in your browser. Re-encode MP3, WAV, AAC, OGG and more at a lower bitrate — files are never uploaded.
Convert Audio
Free online audio converter: turn MP3, WAV, AAC, OGG, FLAC and more into MP3, WAV, M4A or Opus. Converts locally in your browser — no file upload required.