Audio Conversion
Convert M4A to AU Online — Free
Fast, free M4A to AU converter. No registration required.
或从以下导入
200万+文件已转换
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安全传输
HTTPS 加密上传
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文件处理后自动删除
无需注册
即刻开始转换
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任何浏览器，任何设备
如何转换
1
Upload your .m4a 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 .au file when it's ready.
什么是 M4A？
M4A is an audio-only MPEG-4 container, commonly using AAC encoding. It provides better quality than MP3 at similar file sizes.
格式详情
- 全称
- MPEG-4 Audio
- 扩展名
- .m4a
主要特点
- Better than MP3
- Apple ecosystem
- AAC encoding
- Metadata support
什么是 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.
格式详情
- 全称
- Sun Microsystems Audio
- 扩展名
- .au
主要特点
- Unix standard
- Java audio
- Simple format
- Legacy support
M4A 与 AU 对比
| 特性 | M4A | AU |
|---|---|---|
| 全称 | MPEG-4 Audio | Sun Microsystems Audio |
| 扩展名 | .m4a | .au |
| 最适合 | Better than MP3 | Unix standard |
常见问题
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 M4A and AU 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.