100% local
AUDIO

Convert AAC
to AU

Right-sized output for the use case.

Converting from AAC to AU aligns the file with the encoding choices the downstream pipeline expects. The result is a deliverable that fits naturally into the destination workflow.

— Drop area

WHY CONVERT

Why convert AAC to AU

01

Right-sized output for the use case

Converting from AAC to AU aligns the file with the encoding choices the downstream pipeline expects. The result is a deliverable that fits naturally into the destination workflow.

02

Acceptance by downstream tools

AU is the format most receiving systems expect for this kind of content. Converting upstream avoids the rejection and silent re-encoding that often happen when AAC reaches an unprepared pipeline.

03

Portable, predictable file format

AU is well documented and decodable by long-lived tooling, which matters for archives, deliverables, and any file that needs to outlive the software that created it.

— How to convert

AAC to AU in three steps.

  1. 01

    Open LocalConvert

    Visit this page on any modern browser — no install, no signup, no plugin.

  2. 02

    Drop or select your AAC file

    Drag your AAC into the drop area, or click to pick one from your device.

  3. 03

    Click Convert

    Conversion runs entirely in your browser. When it's done, your AU file downloads to your device.

QUALITY & FIDELITY

Quality and fidelity

  • Lossy to lossy: a second generation of compression artifacts is possible.
  • Metadata is dropped: the target format does not carry it natively.
Transparency AAC ✗ AU ✗
Color depth 16-bit stereo audio unknown
Metadata preserved ✗

FORMAT SPECS

Format specifications

AAC
Extensions.aac
MIME typesaudio/aac
Introduced1997
MaintainerISO/IEC (MPEG)
Magic #FF F1
SpecView spec ↗

COMPATIBILITY

Where these formats work

AAC

Windows
Native
macOS
Native
iOS
Native
Android
Native
Chrome
Native
Firefox
Native
Safari
Native
Edge
Native

Why LocalConvert

How LocalConvert compares

CategoryLocalConvertCloud converters
PRIVACYFiles never leave your device. The whole pipeline runs in your browser via WebAssembly.Files travel to a remote server, sit in queue storage, and may be retained for analytics or moderation.
COSTFree, no signup, no daily quotas.Often free for small files; paid tiers for batch / large / commercial use.
LIMITSLimited only by your device's memory and CPU. Uncompressed WAV stems handled comfortably on desktop.Typical 100 MB to 1 GB per-file caps, plus rate limits.
— The formats
From · AAC

Advanced Audio Coding

The successor to MP3 with superior quality per bit. Used widely in streaming and modern audio.

Typical uses
YouTube, Apple Music, streaming services.

To · AU

AU

AU is a file format supported by LocalConvert.

— FAQ

Frequently asked.

Is AAC to AU conversion free?

Yes. LocalConvert is completely free, with no signup and no per-file or per-day limits.

Do my files get uploaded anywhere?

No. AAC to AU conversion happens entirely inside your browser using WebAssembly — your file never leaves your device.

What's the maximum file size?

There's no fixed cap — the practical limit is your device's available memory. Very large files may take longer or fail on low-RAM devices.

Does it work offline?

Yes — once the page has loaded, AAC to AU conversion works without an internet connection. Re-open the page once to cache it.

Will conversion preserve quality?

LocalConvert uses the industry-standard tools (FFmpeg, ImageMagick, Pandoc) — quality matches what professionals use on the command line. Lossy formats will still lose some quality on each re-encode.

— Related

Or convert these.

AAC 3G2AAC 3GPAAC AC3AAC AIFAAC AIFCAAC AIFF
Browse all conversions
REFERENCES

Format references

AAC

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100% local conversion.

AAC to AU is processed in your browser with WebAssembly. No upload, no tracking, no limits. Your file never leaves your device.