Audio Compressor

Shrink an audio file for email, chat, or storage. Target bitrate, optional mono downmix, optional sample-rate downsample.

What it does

Drop an audio file. Pick a target bitrate (32–320 kbps), optionally downmix stereo to mono (halves the data again for spoken content), optionally downsample to 22.05 or 16 kHz for voice content (where the upper frequencies aren't useful).

AAC/M4A and Opus targets are available. Opus usually produces the smallest files at the same perceptual quality.

How to use it

  1. Drop the audio file — Any common audio format.
  2. Pick targets — 128 kbps stereo for music; 64 kbps mono 16 kHz for voice. Opus is usually more efficient than AAC at the same bitrate.
  3. Compress and download — The size summary shows the reduction percentage.

When to use it

Email attachment limits

Shrink a 100 MB raw recording to 5 MB so it fits within email caps.

Podcast archive trim

Spoken-word content at 32 kbps mono 16 kHz is still listenable, and ~10× smaller than the master.

Voice memos

iPhone Voice Memos default to high bitrates. Re-encode to Opus 48 kbps for chat sharing.

FAQ

Will the compression hurt quality?
Lossy compression always loses some fidelity. The defaults (128 kbps stereo) are barely distinguishable from the source for most ears. Below 64 kbps, music starts to sound thin.