How do I convert AAC to AU?

Drop your AAC file onto the converter above, make sure AU is selected, and click Convert. When it's done, download the AU file — it usually takes a few seconds.

Is it safe to convert AAC to AU here?

Yes. AAC to AU conversion happens entirely inside your browser using WebAssembly, so your file is never uploaded to any server.

Is the AAC to AU converter free?

Yes — free with no watermark. Signed-out visitors can convert 25 files a day, and a free account raises that to 250.

Will converting AAC to AU reduce quality?

No — AU preserves the content of your AAC file as faithfully as the format allows.

Can I convert multiple AAC files at once?

Yes. Add up to 5 files at a time without an account, 10 with a free account and up to 500 on paid plans, then download them individually or as a single ZIP.

Can I convert AU back to AAC?

Yes — use our AU to AAC converter. Note that converting back and forth between formats can't recover detail lost to lossy compression.

AU→AAC AAC→MP3 MP3→AU AAC→WAV MP4→AU AAC→M4A WAV→AU AAC→FLAC MOV→AU AAC→OGG M4A→AU AAC→Opus AAC→WMA AAC→AIFF AAC→AMR AAC→M4B AAC→AC3 AAC→MP2 AAC→WEBA AAC→OGA AAC→MKA AAC→WV AAC→TTA WebM→AU FLAC→AU MKV→AU AVI→AU OGG→AU WMV→AU Opus→AU WMA→AU FLV→AU M4V→AU MPEG→AU 3GP→AU AIFF→AU AMR→AU MPG→AU TS→AU M4B→AU MTS→AU VOB→AU PNG→JPG JPG→PNG PNG→WebP JPG→WebP WebP→PNG WebP→JPG HEIC→PNG HEIC→JPG MP4→MP3 PNG→JPEG JPG→JPEG JPEG→PNG JPEG→JPG PNG→PDF JPG→PDF PDF→PNG PDF→JPG HEIC→WebP MP4→WebP PDF→DOCX DOCX→PDF JPEG→WebP WebP→JPEG PNG→GIF JPG→GIF GIF→PNG GIF→JPG MP4→MOV MOV→MP4 WebP→PDF HEIC→JPEG WebP→GIF GIF→WebP HEIC→PDF MP3→WAV WAV→MP3 JPEG→PDF PDF→JPEG SVG→PNG SVG→JPG HEIC→GIF MOV→MP3 MP4→GIF GIF→MP4 JPEG→GIF GIF→JPEG PNG→AVIF JPG→AVIF AVIF→PNG AVIF→JPG MP3→M4A M4A→MP3 GIF→PDF SVG→PDF PNG→SVG JPG→SVG PDF→SVG SVG→WebP MOV→WebP MP4→WAV MP4→WebM WebM→MP4 WebP→AVIF AVIF→WebP WebP→SVG SVG→JPEG MP4→MKV MKV→MP4 HEIC→AVIF MP4→M4A JPEG→AVIF AVIF→JPEG JPEG→SVG MOV→GIF GIF→MOV WebM→MP3 AVIF→PDF MP3→FLAC FLAC→MP3 MP4→AVI AVI→MP4 MKV→MP3 GIF→AVIF AVIF→GIF SVG→GIF GIF→SVG WebM→WebP MOV→WAV XLSX→PDF CSV→PDF EPUB→PDF PDF→EPUB MOV→WebM WebM→MOV MKV→WebP PNG→ICO JPG→ICO ICO→PNG ICO→JPG MP3→AAC WAV→M4A M4A→WAV MP4→FLAC AVI→MP3 MOV→MKV MKV→MOV MOV→M4A DOCX→EPUB EPUB→DOCX CSV→DOCX PDF→TXT DOC→PDF TXT→PDF WebP→ICO ICO→WebP PPTX→PDF AVI→WebP WebM→GIF

AACAU

Convert AAC to AU

Free, fast and private. Your AAC files are converted right in your browser — nothing is uploaded.

Runs in your browser
No watermark
Batch & ZIP download

Need a smaller AAC? Compress AAC

How to convert AAC to AU

1
Add your AAC files
Drag and drop AAC files onto the converter, paste them, or click to browse. You can add several at once.
2
Choose AU
AU is already selected. Open Options if you want to change quality, size or metadata.
3
Convert
Click Convert. Your files are converted right in your browser in seconds.
4
Download your AU
Download each AU file, or everything at once as a ZIP.

AAC vs AU

From

AAC · Advanced Audio Coding

AAC is the successor to MP3, delivering better quality at the same bitrate. It's the default audio codec on Apple devices and YouTube.

Type: Audio
Extension: .aac
MIME: audio/aac
Best for: streaming, mobile audio and video soundtracks

Lossy compression

All AAC conversions →

AU · Sun Audio

AU is a simple audio format introduced by Sun Microsystems, common on early Unix systems and Java.

Type: Audio
Extension: .au
MIME: audio/basic
Best for: legacy Unix and Java applications

Legacy format

All AU conversions →

Need it the other way around? Convert AU to AAC.

Related conversions

AAC to AU: frequently asked questions

Free, private and in your browser

Convert AAC to AU in seconds.

No sign-up, no watermarks, no waiting in line. Drop a file and get it back in the format you need.

Convert a file Explore the API

Most conversions never leave your device
Cloud files deleted automatically
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Convert AAC to AU

How to convert AAC to AU

Add your AAC files

Choose AU

Convert

Download your AU