CDDA to AU Converter

Convert CD audio to Sun/NeXT AU format online

Drop files here. 1 GB maximum file size or Sign Up
to
Facebook Amazon Microsoft Tesla Nestle Walmart L'Oreal

Unix Audio Standard

Convert CDDA to AU — the classic Sun Microsystems format still essential for Unix systems, Java applications, and legacy workflows.

Cross-Platform

AU plays on Unix, Linux, macOS, and Windows. Your converted CDDA audio works across operating systems without codec hassles.

No Local Tools

AU encoding runs on our servers. No SoX installation or Unix command-line knowledge required — convert from any browser.

How to convert CDDA to AU

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose au or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your au file right afterwards

About formats

CDDA (Compact Disc Digital Audio), known as the Red Book standard, defines audio stored on music CDs. Jointly developed by Sony and Philips and published in 1980, it established parameters that shaped digital audio for decades: 16-bit linear PCM at 44.1 kHz stereo, yielding 1,411.2 kbps uncompressed. Each disc holds up to 80 minutes organized into tracks with index points, sub-channel data for text display, and error correction codes (CIRC) ensuring reliable playback despite minor scratches. When audio is ripped from a CD, the resulting stream is often saved with the .cdda extension as raw PCM before conversion. The most obvious advantage is uncompressed, lossless nature — what reaches your ears is mathematically identical to the studio master at the specified resolution. Robust error correction provides excellent resilience, maintaining audio integrity even when disc surfaces suffer moderate wear. Having sold billions of units since the first commercial release in 1982, CDDA established baseline quality expectations for digital music and remains the reference against which compressed codecs are measured.
Developer: Sony / Philips
Initial release: October 1980
AU is an audio file format introduced by Sun Microsystems for its Unix workstations and the NeXT platform. It features a minimal 24-byte header specifying data offset, size, encoding type, sample rate, and channel count, followed by the audio payload. AU supports numerous encodings, including uncompressed linear PCM at various bit depths, mu-law and A-law companding (logarithmic compression used in telephone systems), and several ADPCM variants. This versatility made AU a workhorse across early Unix environments, web audio (Java applets defaulted to AU), and telephony applications. One advantage is simplicity: the compact header and straightforward structure make it trivial to parse, generate, and stream programmatically. The built-in mu-law option provides another benefit, delivering reasonable voice quality at just 8 KB per second — half the rate of 16-bit uncompressed audio — invaluable when storage and bandwidth were scarce. Although modern formats have largely supplanted AU in consumer applications, it retains a foothold in scientific computing and audio processing pipelines where minimal overhead and reliable cross-platform behavior are valued.
Developer: Sun Microsystems
Initial release: 1992

Frequently Asked Questions

Why convert CDDA to AU?

AU is the standard audio format on Unix and Solaris systems. Java javax.sound API also uses AU natively, making it essential for Java audio apps.

What plays AU files?

VLC, Audacity, SoX, and Java-based media players handle AU natively. Unix/Linux systems have built-in AU playback support.

Does AU support CD quality?

Yes — AU with linear PCM encoding stores uncompressed audio matching CDDA quality. Mu-law encoding trades quality for smaller size.

Is AU still relevant?

AU remains important for Java sound programming, Unix system sounds, and legacy Sun/NeXT application compatibility.

Can I batch convert CDDA to AU?

Upload multiple CDDA tracks at once and convert them all to AU — practical for building Unix system sound libraries.