Audio Compressor
NewReduce the file size of your audio files while keeping playback quality as clear as possible.
Your files are processed entirely in your browser. Nothing is uploaded to any server, and your documents never leave your device.
What is Audio Compressor?
An audio compressor (in the file-size sense) re-encodes a sound file at a lower bitrate so it takes up less space. This tool uses the LAME MP3 encoder running in your browser: pick a quality level, and the file is re-encoded locally with the size savings shown when it finishes. A WAV podcast export can easily shrink by 90% with barely audible difference for speech.
Why use Nuo Tools's Audio Compressor?
How to use Audio Compressor
Drop the audio file you want to shrink into the tool.
Pick a quality level - lower bitrates mean smaller files.
Click Compress and watch the progress bar.
Download the smaller MP3 and check the shown savings.
Frequently asked questions
Which quality setting should I use?+
96 kbps is great for speech - podcasts, interviews, voice notes. 128 kbps suits mixed content. Use 64 kbps only when size matters most, and avoid it for music.
How much smaller will my file get?+
WAV files shrink dramatically - typically 85-95%. Existing MP3s shrink in proportion to the bitrate drop: a 320 kbps MP3 re-encoded at 96 kbps becomes about 70% smaller.
Will I hear the difference?+
For speech at 96 kbps, almost never. For music, compression below 128 kbps becomes audible - if the file is music, consider keeping 128 kbps as the floor.
Is my audio uploaded to compress it?+
No. The re-encoding runs in your browser using FFmpeg and the LAME encoder compiled to WebAssembly. The file never leaves your device.
Can I compress an already compressed MP3?+
Yes, but each lossy re-encode stacks a little quality loss. Going from a high bitrate to a lower one once is fine; repeatedly re-compressing the same file degrades it audibly.
When to use this tool
- →Shrinking a WAV recording before emailing it
- →Reducing podcast file sizes for faster uploads and downloads
- →Fitting voice notes into a messaging app attachment limit
- →Archiving many recordings in less storage space
- →Compressing lecture audio for a course site