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Audio Conversion

Convert AU to FLAC Online — Free

Fast, free AU to FLAC converter. No registration required.

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How to Convert

1

Upload your .au file by dragging it into the upload area or clicking to browse.

2

Choose your output settings. The default settings work great for most files.

3

Click Convert and download your .flac file when it's ready.

What is AU?

AU is an audio format created by Sun Microsystems. It's one of the oldest digital audio formats, commonly used on Unix and Java platforms.

Format Details

Full Name
Sun Microsystems Audio
Extension
.au

Key Features

  • Unix standard
  • Java audio
  • Simple format
  • Legacy support

What is FLAC?

FLAC is an open-source lossless audio codec. It compresses audio without any quality loss, making it popular among audiophiles.

Format Details

Full Name
Free Lossless Audio Codec
Extension
.flac

Key Features

  • Lossless compression
  • Open source
  • Audiophile quality
  • Metadata support

AU vs FLAC

FeatureAUFLAC
Full NameSun Microsystems AudioFree Lossless Audio Codec
Extension.au.flac
Best ForUnix standardLossless compression

Frequently Asked Questions

Converting between lossless formats preserves perfect quality. When converting to lossy formats, our optimized encoding minimizes any audible difference. You can adjust bitrate to control quality vs. file size.
We preserve ID3 tags, album art, and metadata when both AU and FLAC support them. Some metadata may not transfer between incompatible formats.
Pro users can batch convert multiple audio files simultaneously. Free users convert one file at a time with up to 5 free conversions per day.
We support all standard sample rates from 8kHz (voice) up to 192kHz (studio quality). The default preserves your source file's sample rate.
Yes. Our audio converter handles music, podcasts, voice memos, and audiobook files. For podcasts, we recommend MP3 at 128-192kbps for the best balance of quality and file size.

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