OGG to AU Converter

How to Convert OGG to AU Online

1. Upload Your OGG File: Drag and drop or click "Choose Files" to add an Ogg Vorbis file. Only .ogg is accepted on this page; for .oga containers use OGA to AU. Batch upload is supported.
2. Pick Audio Channel: Default is Original (keep whatever the OGG has). Choose Mono to halve the file size — useful because classic AU was an 8 kHz mono telephony format. Choose Stereo to upmix or preserve both channels for music and effects.
3. Set Audio Sample Rate (Optional): Leave at Original to match the source, or pick 8000 Hz (telephony / Solaris /dev/audio legacy), 24000 Hz (simple FX, AM-radio quality), 44100 Hz (CD quality, the safest default for Java javax.sound.sampled playback), or 48000 Hz (broadcast / DAW projects).
4. Trim (Optional) and Convert: Switch Trim from "Unchanged" to "Trim" and enter a Start Time and Duration as seconds or HH:MM:SS.sss to crop a region — handy for keeping output files small, since AU stores raw samples rather than perceptually compressed audio. Click Convert and download the .au file. Conversion runs on our servers — no sign-up, no watermark.

Why Convert OGG to AU?

OGG (Ogg Vorbis) is a free, royalty-free lossy container from the Xiph.Org Foundation, popular in games (the Source engine, Unity, Godot all ship Vorbis decoders) and for podcast/streaming pipelines. AU — magic bytes .snd (0x2e736e64), big-endian header — was introduced by Sun Microsystems in the early 1990s and remains the de facto Unix audio format. Converting OGG into AU is uncommon as an end-user task but very common in development and research workflows.

• Java javax.sound.sampled playback — AudioFileFormat.Type.AU is one of only five formats the standard Java Sound API recognizes natively (alongside WAVE, AIFF, AIFC, SND). Shipping .au assets means you can AudioSystem.getAudioInputStream(...) without bundling JOrbis or a Vorbis SPI.
• Legacy Unix / Solaris system sounds — SunOS exposed AU directly through the /dev/audio device, so init scripts, alarm chimes, and SPARCstation-era applications still expect .au. NetBSD and OpenBSD audio tooling still handle AU natively.
• Scientific computing and MATLAB — audioread() accepts .au directly; many older signal-processing datasets (NIST TIMIT, CMU ARCTIC supplements, telephony corpora) are distributed as 8 kHz mu-law AU.
• Reproducible Unix scripting — sox, play, ffmpeg, and Audacity all read/write AU without plugins, so AU is a portable interchange format when you want a deterministic, header-defined PCM file for build pipelines.
• Embedded and DSP prototyping — the AU header is just six 32-bit big-endian words, so a microcontroller or FPGA test bench can stream a raw .au file with about 30 lines of C — far simpler than parsing Vorbis bitstream packets.

OGG (Vorbis) vs AU (Sun/NeXT) — Format Comparison

Sample Rate and Channel Guide for AU Output

Tip: AU output stores a fixed number of bytes per sample (one for the default μ-law, two for optional 16-bit PCM), so output size scales linearly with sample rate and channel count — going from 44.1 kHz stereo to 8 kHz mono drops the file size by ~11x.

Frequently Asked Questions

Why is my AU file so much larger than the source OGG?

OGG Vorbis is lossy MDCT compression typically at 96-192 kbps; AU on this converter writes raw samples — 8-bit μ-law by default, one byte per sample per channel. A 3-minute Vorbis track at 128 kbps is about 2.9 MB; the same audio as 44.1 kHz stereo μ-law in an AU container is about 15.9 MB (44,100 × 2 × 180 bytes), and selecting 16-bit PCM doubles that to ~31.7 MB. To shrink the AU output, switch Audio Channel to Mono and Audio Sample Rate to 24000 Hz or 8000 Hz.

Which AU encoding does this converter produce — mu-law, A-law, or linear PCM?

The default output is 8-bit mu-law (encoding 1) — the classic SPARC-era /dev/audio profile. 8-bit A-law (encoding 27) and 16-bit signed big-endian linear PCM (encoding 3, PCM_S16BE) are selectable in the advanced options. The AU specification supports many more encodings — 8/16/24/32-bit signed linear PCM (encodings 2-5), 32/64-bit IEEE float (encodings 6-7), plus various G.722/G.723 ADPCM modes (23-26) — but those three are what this converter writes. Pick PCM_S16BE if you want the Java-friendly full-fidelity variant.

Will Java's AudioSystem.getAudioInputStream() play these files?

Yes. AudioFileFormat.Type.AU is one of five formats the JDK recognizes natively (the others are WAVE, AIFF, AIFC, SND), so you do not need a third-party SPI like JOrbis or Tritonus. Pick 44100 Hz Stereo for music assets and 24000 Hz Mono for short UI sounds and the output will load and play through any standard Java audio mixer.

Why are there no bitrate or compression options on this page?

The AU output on xconvert writes a fixed number of bytes per sample — 8-bit μ-law by default, 16-bit PCM if selected — so there is no encoder bitrate to tune; file size is fully determined by sample rate × bytes per sample × channel count × duration. The variables you can change are Audio Channel (Mono/Stereo), Audio Sample Rate (8000-48000 Hz), and Trim. For a compressed lossless alternative use OGG to FLAC; for a smaller lossy target use OGG to MP3.

Does the AU file preserve OGG metadata like artist and album tags?

No. Vorbis comments (UTF-8 key/value tags such as ARTIST, ALBUM, TITLE) do not have a direct equivalent in AU. AU only supports an optional ASCII annotation chunk between the header and the audio data, and most tools (Audacity, Java Sound, sox) ignore it. If you need tagged distribution files, convert to OGG to M4A or MP3 instead.

Can I trim a long OGG and only export a segment as AU?

Yes — under Trim, switch from "Unchanged" to "Trim" and enter a Start Time and Duration. Values accept either plain seconds (12.5) or HH:MM:SS.sss (00:00:12.500). Because AU stores raw samples, trimming is the most effective way to keep the output small: a 10-second mono 24000 Hz clip is about 240 KB at the default μ-law (about 480 KB as 16-bit PCM), while the full 4-minute track at the same settings is about 5.8 MB (μ-law) or 11.5 MB (PCM).

What plays an AU file on Windows or macOS today?

VLC and Audacity open AU on every platform. macOS QuickTime Player and Windows Media Player do not handle AU natively — on Windows you can register a codec or use ffplay from FFmpeg, on macOS use afplay (Core Audio handles AU) or sox. Browsers do not play AU natively; if you need web playback, target OGG to MP3 or OGG to WAV.

Is this conversion lossy or lossless?

It is technically lossy because OGG Vorbis itself is lossy — the Vorbis decoder reconstructs an approximation of the original PCM, and that approximation is what gets written into the AU container. Going OGG → AU adds no further loss only if you select 16-bit linear PCM (PCM_S16BE) in the advanced options; the default 8-bit μ-law is telephony-grade companding and shaves off a little more. Either way the output cannot have higher fidelity than the OGG input. For best results, start from the highest-bitrate OGG you have and pick 44100 Hz Stereo to avoid resampling artifacts.

Can I convert multiple OGG files at once?

Yes. Add as many .ogg files as you need in one batch and each is processed and downloadable independently. For format-mixing pipelines (mp3, flac, m4a, wma, oga sources alongside ogg), use the generic Audio to AU page instead, which accepts every supported audio extension in a single drop.