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
大切な音声ファイル、AU形式からFLACへの変換をお考えですか？ AUは古くから使われる音声形式ですが、高音質とファイルサイズの効率性で知られるFLACへの変換は、音源をより良い形で保存し、活用するための賢い選択と言えるでしょう。特に、繊細な音のニュアンスを大切にする日本のユーザーにとって、可逆圧縮であるFLACは、音質劣化の心配なくアーカイブや共有を行う上で理想的な形式です。このページでは、お手持ちのAUファイルをFLACへスムーズに変換し、その高音質を存分に引き出すためのお手伝いをさせていただきます。簡単な操作で、あなたの音源が新たな息吹を得る過程をぜひ体験してください。
- 同人音楽の高音質アーカイブ
- ビジネス会議録の長期保存
- ASMR音声の原音忠実な共有
AUファイルは、かつて日本のアニメやゲーム制作の現場で効果音などに利用されるケースが多く見られました。FLACへの変換は、これらの貴重な音源を現代の環境で再活用する上で非常に有効です。
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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