How do I convert AU to FLAC?

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

Is it safe to convert AU to FLAC here?

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

Is the AU to FLAC 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 AU to FLAC reduce quality?

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

Can I convert multiple AU 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 FLAC back to AU?

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

FLAC→AU AU→MP3 MP3→FLAC AU→WAV MP4→FLAC AU→M4A WAV→FLAC MOV→FLAC AU→AAC M4A→FLAC AU→OGG WebM→FLAC AU→Opus AU→WMA AU→AIFF AU→AMR AU→M4B AU→AC3 AU→MP2 AU→WEBA AU→OGA AU→MKA AU→WV AU→TTA MKV→FLAC AAC→FLAC AVI→FLAC OGG→FLAC WMV→FLAC Opus→FLAC WMA→FLAC M4V→FLAC 3GP→FLAC FLV→FLAC MPEG→FLAC AIFF→FLAC AMR→FLAC TS→FLAC MPG→FLAC M4B→FLAC MTS→FLAC VOB→FLAC 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 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 AAC→MP3 M4A→WAV 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 GIF→WebM

AUFLAC

Convert AU to FLAC

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

Runs in your browser
No watermark
Batch & ZIP download

How to convert AU to FLAC

1
Add your AU files
Drag and drop AU files onto the converter, paste them, or click to browse. You can add several at once.
2
Choose FLAC
FLAC 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 FLAC
Download each FLAC file, or everything at once as a ZIP.

AU vs FLAC

From

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 →

FLAC · Free Lossless Audio Codec

FLAC compresses audio without losing any quality, typically halving the size of a WAV file.

Type: Audio
Extension: .flac
MIME: audio/flac
Best for: archiving CDs and high-fidelity music libraries

LosslessOpen standard

All FLAC conversions →

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

AU to FLAC: frequently asked questions

Free, private and in your browser