What is a .AU file?
AU is the Sun/NeXT audio format, one of the oldest digital sound formats.
- Did you know
- The AU format comes from Sun Microsystems in the late 1980s. (approximate)
- The AU header is six 32-bit words stored big-endian regardless of the machine, recording the data offset, size, encoding, sample rate and channel count.
- NeXT used the same format with a .snd extension, and it became the default sound format for early Java audio.
- What Analyser reads
- Identify many more audio formats: lossless/hi-res codecs (Monkey’s Audio, WavPack, TAK, True Audio, DSD/SACD, Musepack), pro containers (Core Audio, RF64/BW64, Wave64, Sun AU, Broadcast Wave with timecode), speech/mobile (Speex, AMR-WB, QCP, 3GA, M4R, GSM), MPEG Layer I/II, instrument banks (SoundFont, SFZ, DLS, RIFF MIDI, GigaStudio), ringtones (RTTTL, iMelody, SAP), tracker modules (MOD, XM, IT, S3M, OctaMED, 669, Oktalyzer), chiptunes (NES NSF, SNES SPC, VGM, Game Boy GBS, AY, YM) and Audacity projects.
- Depth of analysis
- .AU is an identification-grade format: Analyser recognises it from its bytes and decodes the header metadata it carries, rather than opening it in a full viewer. Formats that do get a full viewer are marked "Full" on the formats page.
- Open a .AU file
- Drag a .AU file onto the Analyser home page (or tap to pick one). It is identified entirely in your browser - nothing is uploaded, there is no account, and it works offline once installed.