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Audio Compressor

Compress audio files to reduce size

Click to upload an audio file

About Audio Compressor

Audio Compressor reduces an audio file's size by re-encoding it at a lower bitrate (64–320 kbps) using ffmpeg.wasm, entirely in your browser. Note: this is bitrate-based file-size compression — it does not apply dynamic-range compression (threshold/ratio/attack/release) despite the tool's name.

How to use Audio Compressor

  1. 1Click the upload area and select an audio file.
  2. 2Choose a target bitrate from the presets (64k–320k).
  3. 3Click "Compress Audio" to re-encode the file locally.
  4. 4Compare the before/after size and download the result as MP3.

Frequently Asked Questions

Does this apply dynamic-range compression?

No — despite the name, this tool re-encodes your audio at a lower bitrate to shrink file size. It doesn't touch the audio's dynamic range (loud vs. quiet parts).

What output format do I get?

Always MP3, regardless of the format you uploaded.

Is there a file size limit?

No hard limit is enforced by the tool — very large files are limited only by your browser's available memory.

Is my file uploaded anywhere?

No. Everything is processed client-side via ffmpeg.wasm — nothing is uploaded to a server.

Tips & Tricks

  • ✓128 kbps is a reasonable default for most music; drop to 64–96 kbps for voice-only content where size matters most.
  • ✓Lower bitrates noticeably reduce quality for complex music — compare the audio preview before committing.
  • ✓The first compression after loading the page takes longer since the ffmpeg.wasm engine needs to download.
  • ✓If you need real dynamic-range compression (leveling loud and quiet parts), you'll need a dedicated audio-editing tool — this one only changes bitrate.