Compress AAC online

Smaller AAC files, same AAC format—server-side processing.

Drag & drop files here or browse. Max file size 100 MB for your account. Sign up or view pricing.

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Compression results

How your files are processed

Files are uploaded and processed on our servers, then made available for download.

What this tool does

Re-encode AAC audio with smaller size settings while keeping AAC as the output format. The encoder rebuilds the AAC bitstream using your chosen bitrate or quality target; output stays AAC.

AAC output remains AAC — Input and output stay Advanced Audio Coding; this profile does not switch you to another codec.
Lossy recompression — Each pass removes frequency detail; stronger settings save more space but raise the risk of audible artifacts.
Bitrate shapes size and clarity — Target bitrate and encoder profile set the size-to-quality tradeoff for the same AAC output.

How to compress AAC files?

Choose file — select a AAC file that matches this compressor (allowed extensions apply).
Adjust options — set quality, level, or advanced options if shown, then compress.
Download — grab the smaller file from your job page when processing completes.

Why compress AAC files?

Choose AAC compression when you need smaller audio files and can accept lossy tradeoffs. Use gentler settings for music and stronger settings for speech drafts. Park an editor bounce or 24-bit off-disk if you might recut; stacked AAC passes add grit.

Common uses for AAC compression

Upload AAC voice notes to a CMS when attachment limits block larger files.
Prepare AAC previews for client review where smaller downloads matter.
Shrink long AAC recordings before syncing to a laptop with little free disk space.
Export a lighter AAC version for mobile playback when the export used an unnecessarily high bitrate.
Submit AAC creatives to ad platforms that cap file size per placement.
Post blind A/B listens in Slack before deleting master recordings.

Will compressing AAC (AAC) affect quality?

Low targets dull air, smear attacks, or add pre-echo on sibilance. Audition speech and mixes on headphones before you overwrite the sole session. Dense cymbal beds need higher kbps than narrowband VO.

How AAC compression works

Bitrate headroom

AAC streams may still use more bits than the content needs—simple speech and silence often compress smaller than dense stereo mixes suggest.

What changes in the encode

Re-encoding applies a new AAC encode with your chosen average or constant bitrate; frames are rebuilt while the format remains AAC.

Stronger compression discards more masked spectral detail; small bitrate steps often matter more for full mixes than for single-voice speech.

Troubleshooting

Lean exports may resist big wins: some AAC sources were saved with tight settings already.
Quality trade-offs are expected: stronger compression can introduce artifacts.
Bitrate settings matter: lower targets shrink files but can thin vocals on dense mixes.
Long tracks take longer: duration affects processing time.

AAC compression FAQ

Often not at moderate settings. Very low targets can dull highs or add swishy artifacts—raise bitrate or use gentler quality if you hear problems.

Tiny durations, mostly silence, or an export that was already lean leave little fat. Another encode cannot invent megabytes that were never there.

Each pass stacks grit. Re-render from the DAW bounce or archival when you need another attempt—not from another compressed AAC.

Speech-only material often tolerates lower targets than full stereo mixes. Start higher for dense music; dial down only if clarity stays acceptable on headphones or car speakers.