Turn AU audio files into FLAC. It is converted in your browser, so the file never leaves your device.
Drop AU files here
or choose from your computer paste with Ctrl V
from Photos or Files
Ready · other file types work too0 bytes uploaded, ever
Drop AU (SND) files onto the box above, or click it to choose them. ToAny reads the file's contents to detect the type, so a wrong extension does not matter.
Press Convert. Open Options first if you want to change the defaults. The work happens in this tab.
Save the FLAC, or download everything as one ZIP if you converted several files.
The AU to FLAC converter is part of this page and runs inside your browser. Your audio files are never sent to ToAny or to anyone else.
Nothing has to travel to a server and back, so the conversion starts the moment you press Convert, even on a slow connection.
No sign-up, no email address and no watermark. Add several files and download them together as a ZIP.
AU is dated and is rarely accepted by modern apps. FLAC keeps full quality at about half the size of WAV. An AU file usually holds PCM, or μ-law and A-law telephone encoding. AU is at home in simple uncompressed audio and Unix and Java sound clips; FLAC is the usual choice for archiving music at full quality.
The defaults suit most files. Under Options you can trim the start and end.
This pair uses the compatibility engine, ffmpeg built for the browser, because AU is not handled by the browser's built-in codecs. It is a one-off download of about 10 MB that the browser keeps, it is slower than the built-in codecs, and it takes files up to 1 GB.
AU is one of the oldest audio containers: a short header followed by the samples. It comes from Sun workstations and NeXT, was the sound format of early web pages and Java, and often holds 8-bit μ-law telephone audio. Newer files can hold 16-bit PCM or floating point.
Opens in Audacity, VLC, QuickTime and most audio editors
AU converterFLAC compresses audio to roughly half the size of WAV without losing anything, like a ZIP for sound. It is the standard for lossless music collections. Apple's Music app is the notable holdout.
Opens in Android, Windows, VLC, most hi-fi players; Apple Music does not import it
FLAC converter| AUSun AU audio | FLACFLAC audio | |
|---|---|---|
| Stands for | Sun/NeXT audio file (AU or SND) | Free Lossless Audio Codec |
| Type | Audio | Audio |
| Compression | Usually none | Lossless |
| Introduced | The late 1980s, by Sun Microsystems | 2001, by Josh Coalson and the Xiph.Org Foundation |
| Opens in | Audacity, VLC, QuickTime and most audio editors | Android, Windows, VLC, most hi-fi players; Apple Music does not import it |
| Best for | Simple uncompressed audio and Unix and Java sound clips | Archiving music at full quality |
| File extension | .au, .snd | .flac |
No. The AU to FLAC conversion runs inside your browser, on your own phone or computer. The file is not sent to ToAny or to anyone else.
No further quality is lost: FLAC stores the decoded audio exactly. The result is identical in content.
Yes. Add as many as you like, convert them together and download each result or all of them as one ZIP.
The steps are the same everywhere because ToAny runs in the web browser: open this page in a current version of Chrome, Edge, Safari or Firefox, add the AU file, press Convert and save the FLAC. There is nothing to install.
Yes. AU to FLAC runs on the compatibility engine, which takes files up to 1 GB, and a long clip takes a while because it is slower than the browser's built-in codecs. Beyond that the limit is your device's memory, since nothing is uploaded; a computer copes with large files better than a phone.