MKV to AU Converter

Extract Sun AU audio from MKV video files online

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Unix and Java Standard

AU is the native format for Sun/NeXT systems and Java audio. Converting MKV audio to AU fits Unix and Java development workflows.

Rapid Processing

Audio-only extraction runs fast. The MKV to AU conversion finishes almost instantly — no video encoding overhead whatsoever.

Cross-Platform Tool

Access the converter from any browser — Windows, macOS, or Linux. No platform-specific tools needed for MKV to AU conversion.

How to convert MKV 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

MKV (Matroska Video) is an open-standard multimedia container format developed by the Matroska project, which announced the format in December 2002. Named after the Russian matryoshka nesting dolls, the format is built on the Extensible Binary Meta Language (EBML), a simplified binary variant of XML that provides a flexible and forward-compatible structure. MKV can hold virtually unlimited numbers of video, audio, and subtitle tracks within a single file, supporting codecs from H.264 and HEVC to VP9 and AV1 for video, and AAC, FLAC, Opus, and DTS for audio. A standout feature is comprehensive subtitle support, handling formats from simple SRT text to complex ASS styled subtitles and bitmap-based PGS tracks from Blu-ray discs. MKV also supports chapter markers, attachments (such as fonts needed for styled subtitles), and tagging metadata, making it one of the most feature-rich containers available. The open specification ensures that any developer can implement MKV reading and writing without licensing fees, which has driven widespread adoption across media players, streaming tools, and encoding software. The ability to encapsulate virtually any codec combination in a single, well-organized file has made MKV the preferred container for high-quality video distribution, archival, and personal media libraries.
Developer: Matroska
Initial release: December 6, 2002
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 MKV to AU?

AU is the native audio format for Sun/NeXT Unix systems and Java's AudioSystem API. Essential for Unix audio workflows and Java development.

What opens AU files?

Audacity, SoX, VLC, and any Unix/Linux audio application handle AU natively. Java programs using javax.sound also read AU directly.

Is AU still used today?

AU remains relevant in Unix environments, Java audio development, and certain scientific computing applications where it is a standard input.

How does AU compare to WAV?

Both can store uncompressed PCM audio. AU uses big-endian byte order (Sun heritage), while WAV uses little-endian (Intel heritage).

Is the conversion fast?

Very — audio extraction from MKV bypasses video processing entirely. Your AU file is ready in seconds on convertio.tools.

MKV to AU Quality Rating

5.0 (3 votes)
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