AU to SNDR Converter

Free online tool for AU to SNDR conversion

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Remote Conversion

The heavy lifting of converting AU to SNDR runs on our servers, keeping your machine responsive throughout.

Quality Preserved

The AU to SNDR conversion maintains maximum audio fidelity. Your recordings come through clean, without unnecessary artifacts.

Bulk Conversion

Convert an entire folder of AU recordings to SNDR at once. Just upload all files and let the batch converter handle the rest.

How to convert AU to SNDR

1

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

2

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

3

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

About formats

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
SNDR is the audio file format produced by Sounder, an early MS-DOS sound recording and playback utility from the early 1990s. Before Windows brought multimedia to the mainstream, Sounder was among a handful of DOS programs that let PC users capture and play audio through rudimentary hardware — often the PC speaker itself or early 8-bit sound cards. The format stores 8-bit unsigned PCM samples without any file header, relying on application defaults to determine playback parameters. Sample rates were typically low (4000 to 11025 Hz), reflecting hardware limits and storage costs when a 20 MB hard drive was considered generous. One practical advantage was absolute minimalism — with zero overhead bytes, every bit of the file was audio data, which mattered when storage was measured in kilobytes. The format could be piped directly to sound hardware without parsing, making real-time playback feasible on slow processors. Despite its simplicity, SNDR holds a place in computing history as one of the formats that brought digital audio to ordinary PCs. Files from this era occasionally surface in retrocomputing archives. SoX and ffmpeg can interpret SNDR files given the correct parameters, enabling preservation of early digital audio recordings.
Developer: Sounder (MS-DOS)
Initial release: 1991

Frequently Asked Questions

Why convert AU to SNDR?

AU files are tied to UNIX and Java ecosystems. Converting to SNDR makes your audio accessible on any platform.

Which software plays SNDR?

SNDR can be opened with SoX, Audacity, command-line audio tools. Most modern audio applications handle this format without issues.

How is audio fidelity handled during conversion?

The converter preserves maximum fidelity. If SNDR is lossless, no data is discarded. Lossy codecs apply minimal perceptible compression.

Does the converter support batch AU conversion?

Absolutely. You can upload a batch of AU files and convert them all to SNDR together, saving significant time on large collections.

Are my AU uploads kept private?

Yes. Uploaded AU files are deleted right after conversion, and the SNDR output is removed from our servers within 24 hours automatically.

Do I need to install anything?

No installation needed. The AU to SNDR converter is fully browser-based — open the page, upload your audio, and download the result.