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.
About this tool
This audio compressor re-encodes your audio at a lower bitrate to significantly reduce file size — ideal for voice messages, podcasts and email attachments. Choose MP3 for the best compatibility, AAC (M4A) for Apple devices, WAV for lossless quality, or Opus for the smallest size. Everything runs locally in your browser.
How to use
- Click or drag to select an audio file
- Choose the output format and a lower bitrate
- Compare the file size before and after
- Click download to save the compressed audio
FAQ
Which output format should I choose?
MP3 plays on virtually any device and is the safest choice. Opus (WebM) is smaller at the same quality but is not supported by Safari and some players. WAV is lossless but produces large files.
What bitrate should I use?
For speech, 64–96 kbps is usually enough. For music, 128 kbps is a good balance; 192 kbps or more if you are picky about quality.
When should I pick AAC (M4A)?
AAC keeps slightly better quality than MP3 at the same bitrate and is the best-supported format on Apple devices. It works in every modern browser, including ones where Opus encoding is unavailable.
Are my audio files uploaded to a server?
No. All processing runs locally in your browser. Your files never leave your device.
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