Compress Audio Files
Shrink MP3, WAV, M4A and more — choose the bitrate
To compress an audio file, drop it above, choose a bitrate and output format, and click Compress. Fylo re-encodes it in your browser at the size you need — 96 kbps MP3 is about a tenth of a WAV. If the result isn't smaller than your file, Fylo keeps the original. Nothing is uploaded.
Drop audio files here
or tap to browse · paste with Ctrl+V · add many at once
Your files never leave your device
Advanced
How to compress Audio
Add audio files
Drop WAV, MP3, M4A, FLAC, OGG or even video files.
Pick bitrate and format
96 kbps MP3 suits speech; Opus gives the best quality at low bitrates.
Compress and download
Click Compress and download the smaller files or a ZIP.
Choosing a bitrate
Bitrate decides size: at 96 kbps a minute of audio takes about 0.7 MB, at 128 kbps about 0.96 MB. Speech — podcasts, lectures, voice notes — sounds clear at 64–96 kbps, especially in Opus or AAC. Music benefits from 128–160 kbps. Lossless WAV and FLAC files see the biggest savings, often 85–95%.
Which format to pick
MP3 plays absolutely everywhere. M4A (AAC) sounds better than MP3 at the same bitrate and is native to iPhones. Opus is the most efficient of all — 64 kbps Opus beats 128 kbps MP3 for voice — but some older players can't open it. Re-compressing an already-small MP3 to a lower bitrate adds audible artefacts, so start from the best source you have.
| Format and bitrate | Size | Good for |
|---|---|---|
| WAV (CD quality) | ≈ 635 MB | Editing |
| MP3 128 kbps | ≈ 58 MB | Music, universal |
| MP3 96 kbps | ≈ 43 MB | Speech |
| Opus 64 kbps | ≈ 29 MB | Voice, podcasts |
Frequently asked questions
Will compressing audio reduce quality?
Lossy compression removes some detail; at the suggested bitrates most listeners won't notice.
Can I compress a video's audio?
Yes — drop a video and you'll get a compressed audio file of its soundtrack.
Can I compress to mono?
Yes, under Advanced. Mono halves the data needed and is fine for speech.
What if my MP3 is already small?
If compressing wouldn't make it smaller, Fylo keeps your original.
Does it keep the original file name?
Yes, with -compressed added, so you can keep both versions side by side.
Which format gives the smallest files?
Opus at 64 kbps is the smallest for good-sounding speech; M4A (AAC) is the best compromise for music on Apple devices.
Are my files uploaded to a server?
No. Compress Audio runs entirely in your browser — your files are processed on your own device and never sent anywhere. Once the page has loaded, it even keeps working if your connection drops.
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