Compress AAC

How to Compress AAC Audio Online

1. Upload Your AAC File — Click "Choose Files" or drag and drop your .aac audio. Batch compression is supported.
2. Choose Compression Method — Under "File Compression," the default is "File Size Percentage" (default 80% — a 10 MB file becomes 8 MB). Other options:
   • Specific file size: Target an exact output size (default 8 MB)
   • Custom Bitrate: Enter any value in bps, Kbps, or Mbps (default 64 Kbps)
   • Constant Bitrate: Pick from presets (default 64 kbps)
   • Variable Bitrate: AAC ranges like 96k–112k down to 20k–32k
3. Set Audio Channel (Optional) — Keep original, force Mono, or force Stereo. Downmixing to Mono halves the file size.
4. Set Sample Rate (Optional) — Keep original or choose 8000, 12000, 16000, 24000, 44100, or 48000 Hz. Lower sample rates reduce file size.
5. Trim (Optional) — Set a start time and duration in seconds or HH:MM:SS.sss to keep only a segment.
6. Compress and Download — Click "Compress" and download your smaller AAC file. No sign-up required.

Why Compress AAC Files?

AAC (Advanced Audio Coding) is already an efficient lossy codec — the default format for Apple Music, YouTube, and most streaming services. Compressing AAC further reduces file size by lowering the bitrate, which is useful for meeting upload size limits, reducing mobile data usage, or fitting more audio on storage-constrained devices.

Frequently Asked Questions

What bitrate should I target?

64 kbps (default) is acceptable for speech/podcasts. 128 kbps for music. 256 kbps for high-fidelity. Below 48 kbps, quality degrades noticeably.

Will compression reduce audio quality?

Yes — AAC is already lossy, so further compression removes more audio data. Use the highest bitrate that meets your file size requirement.

Can I batch compress?

Yes. Upload multiple AAC files and download results individually or as a ZIP archive.