How to Convert AU to FLAC — Quick & Free
Fast, instant AU to FLAC conversion. No signup required. Just drop your .au file and get .flac in seconds.
Batch Settings
您是否正为音频文件格式转换而烦恼？尤其是当您手头有AU格式的音频，却发现它在日常使用中显得有些“水土不服”时。AU作为一种历史悠久的音频格式，虽然在特定场景下仍有其价值，但在当下这个追求高效、高音质体验的时代，它在兼容性、文件大小以及跨平台分享方面，确实不如FLAC这般主流且备受青睐。FLAC以其无损压缩的特性，不仅能保留原始音频的每一个细节，体积也远小于未压缩的AU文件，无论是传输、存储还是播放，都更为便捷。现在，是时候让您的AU音频华丽转身，拥抱FLAC的无损魅力了！
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在华语地区，随着高音质音乐流媒体和便携设备的普及，用户对无损音频的需求日益增长。将AU转换为FLAC，能更好地适应主流平台和设备的播放要求，避免因格式问题造成的播放障碍或音质损耗。
About AU to FLAC Conversion
Short answer: yes, you can convert AU to FLAC online for free, and quality is well preserved with the right settings. Just upload your .au file to CocoConvert, pick FLAC as the output, and click Convert. The whole process takes seconds.
Now for the details. AU is a widely used file format. FLAC is lossless audio compression — bit-for-bit identical to the original at roughly 50-70% of WAV size. Converting between these two formats lets you convert between formats quickly.
Your AU file is decoded and re-encoded as FLAC. Converting AU to FLAC maintains high quality with CocoConvert's optimised encoder settings.
CocoConvert runs entirely online — no software to install, no account to create. Your files are encrypted during upload (TLS), processed on isolated servers in Germany, and permanently deleted after 24 hours. It works in Chrome, Safari, Firefox, Edge, and all mobile browsers.
Need to convert more than one file? Free users can do 5 per hour. Pro gets 100 per hour with files up to 5 GB each.
How to Convert AU to FLAC
- 1
1. Upload AU
Drop your .au file onto the page (or tap "Browse" on mobile). Add multiple files for batch conversion.
- 2
2. Select FLAC
Choose .flac from the output dropdown. Settings are pre-configured for best results.
- 3
3. Convert
One click. The server handles all the heavy lifting using FFmpeg and Sharp.
- 4
4. Download
Your .flac file is ready. Download it directly or get all files as a zip archive.
What Happens When You Convert AU to FLAC
Your AU file is decoded and re-encoded as FLAC.
Your AU file is uploaded and validated
The file is decoded (parsed into its raw data)
The data is re-encoded in FLAC format
The converted file is ready for download
Format Comparison
AU
.au file
| Extension | .au |
| MIME Type | audio/basic |
| Category | Audio |
FLAC
.flac file
| Extension | .flac |
| MIME Type | audio/flac |
| Category | Audio |
Should You Convert AU to FLAC?
When to Convert
- ✓When you need a FLAC file
Frequently Asked Questions
Is AU to FLAC conversion free?
Yes. CocoConvert offers free AU to FLAC conversion with generous daily limits — 25 minutes of processing time and up to 5 files per hour (250 MB each). Pro plans remove these limits.
How fast is AU to FLAC conversion?
Most files convert in 2–10 seconds depending on size. Large audio files may take 30 seconds. Batch jobs process in parallel for maximum speed.
What happens to my files after conversion?
Your uploaded AU file and the converted FLAC file are both automatically deleted from our servers within 24 hours. They are never shared, sold, or analysed.
Does converting AU to FLAC lose quality?
Converting AU to FLAC maintains high quality with CocoConvert's optimised encoder settings.
Can I convert FLAC back to AU?
Yes, CocoConvert supports FLAC to AU conversion as well. However, if the original conversion involved lossy compression, converting back won't recover the lost data.
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