Online AU Audio Player - Play AU and SND Files in Your Browser
Why Use Our Online AU Player?
Play AU and SND audio files instantly without downloading software. Perfect for legacy audio, Unix workstation files, and early web audio content.
Instant Playback
Play AU and SND audio immediately in your browser. No waiting for downloads or software installations.
Audio Visualization
View waveforms and frequency spectrum while listening to your AU audio files in real time.
Format Details
View encoding type, sample rate, channel count, and other technical details from the AU file header.
100% Private & Secure
All audio processing happens locally in your browser. Your AU files never leave your device.
No Download Required
Play AU audio in your browser. No software installation, no plugins, no registration needed.
Legacy Format Support
Open old AU and SND files from Unix workstations, NeXT systems, and early web archives without needing legacy software.
How to Play AU Audio Files Online
Listen to AU and SND audio in three simple steps — no software download required
Upload Your AU or SND File
Click upload or drag and drop your AU or SND file into the player. The player supports all standard AU file encodings including µ-law (G.711), A-law, 8-bit PCM, 16-bit PCM, 32-bit PCM, and floating-point formats. Files from Sun Microsystems workstations, NeXT computers, and early web audio archives are all supported.
Your audio loads instantly in the browser without uploading to any server, so your legacy audio files and private recordings stay completely secure.
Listen with Full Controls
Audio starts playing automatically with complete playback controls. Use play/pause, seek through the timeline, adjust volume, and view real-time audio visualization with waveforms and frequency spectrum.
View technical details from the AU file header including encoding format, sample rate, number of channels, and data offset, giving you a complete picture of the file structure.
Enjoy Seamless Playback
Experience smooth audio playback with hardware acceleration support. The player handles the AU format's various encoding types automatically, so you hear the audio correctly regardless of how the file was originally created.
Works on all devices including desktops, laptops, tablets, and smartphones. Compatible with Chrome, Firefox, Safari, Edge, and all modern browsers on any platform.
What Is the AU Audio Format?
AU is a simple audio file format introduced by Sun Microsystems in the late 1980s for use on their Unix workstations. The format was also adopted by NeXT computers, where it used the .snd extension, and became one of the first audio formats widely used on the early web due to its simplicity and native support in early browsers like Netscape Navigator. AU files begin with a magic number (.snd) followed by a header containing the data offset, data size, encoding type, sample rate, and number of channels. The format supports a variety of audio encodings including µ-law companding (G.711), A-law companding, 8-bit linear PCM, 16-bit linear PCM, 24-bit PCM, 32-bit PCM, and 32-bit and 64-bit floating-point formats. The µ-law encoding at 8 kHz mono was the most common configuration, used extensively for telephone-quality voice audio on early Unix systems and web pages.
While AU files are rarely created today, they remain relevant for accessing legacy audio archives, Unix system sounds, historical web content, and audio from older scientific and engineering applications. Many Unix and Linux system sound effects were historically stored in AU format, and large archives of early internet audio content still exist in this format. The AU format's simplicity — a minimal header followed by raw audio data — makes it easy to parse and decode, which is why it has remained supported in audio software for decades. Understanding the AU format is valuable for digital archivists, audio engineers working with legacy systems, and developers maintaining compatibility with older Unix-based applications.
Key Features of the AU Format
- Simple Structure: Minimal header followed by raw audio data — one of the simplest audio file formats ever designed
- Multiple Encodings: Supports µ-law, A-law, 8/16/24/32-bit PCM, and 32/64-bit floating-point audio data
- Unix Native: The standard audio format on Sun Microsystems and NeXT workstations throughout the 1980s and 1990s
- Early Web Audio: One of the first audio formats supported by web browsers, widely used for web audio in the mid-1990s
- Dual Extension: Uses both .au (Sun Microsystems) and .snd (NeXT) extensions for the same underlying format
- Telephony Support: µ-law and A-law encodings are the same companding standards used in telephone networks worldwide
AU vs Other Audio Formats
- AU vs WAV: Both can store uncompressed PCM audio, but WAV became the dominant format on Windows while AU remained Unix-centric. WAV has richer metadata support and broader modern compatibility.
- AU vs AIFF: AIFF was Apple's equivalent to AU for Macintosh systems. Both are uncompressed formats from the same era, but AIFF has better metadata support and remains in use today for professional audio on macOS.
- AU vs MP3: AU stores uncompressed or lightly compressed audio while MP3 uses lossy compression for much smaller file sizes. AU is better for archival and legacy compatibility; MP3 is better for distribution and storage efficiency.
Common Uses for AU Audio Files
Legacy Archive Access
Opening and playing audio from Unix workstation archives, early internet audio collections, and historical digital audio recordings stored in AU format.
Unix System Sounds
Playing system notification sounds and audio effects from older Unix, Linux, and Solaris installations that stored their sound files in AU format.
Telephony & VoIP
AU files using µ-law or A-law encoding are directly compatible with telephone network audio standards. Voicemail systems and PBX equipment often produce AU files.
Scientific & Engineering
Audio data from scientific instruments, engineering applications, and research tools that ran on Sun Microsystems workstations and output audio in AU format.
Related Audio Tools
Explore our other legacy and uncompressed audio format players
WAV Player
Play uncompressed WAV audio files — the Windows equivalent of AU from the same era.
AIFF Player
Play AIFF audio files — Apple's uncompressed audio format from the same generation as AU.
FLAC Player
Play lossless FLAC audio files — the modern open-source alternative for archival-quality audio.
MP3 Player
Play MP3 audio files online — the most widely supported lossy audio format.
CAF Player
Play CAF audio files — Apple's modern Core Audio Format that succeeded AIFF for macOS and iOS.
All Audio Tools
View all supported audio formats and online players in one place.
Frequently Asked Questions
What is an AU file?
The AU file format is a simple audio file format introduced by Sun Microsystems. It was common on NeXT and Sun Unix workstations and on early web pages. AU files use the .au or .snd extension and support various encodings including µ-law, A-law, and PCM.
What is the difference between AU and SND files?
AU and SND files use the same format. The .snd extension was used on NeXT systems while .au was used on Sun Microsystems workstations. Both share the same file structure and can be played by the same software.
How do I play AU files on modern systems?
Most modern media players have dropped native AU support. Our online player handles AU and SND files directly in your browser without any additional software or plugins required.
Is it safe to play AU files online?
Your files are never uploaded to any server. All processing happens locally in your browser, so your audio remains completely private and secure at all times.
Start Playing AU Audio Now
Free, fast, and secure. No download or registration required.