AU vs SPX — Comparison & Free Converter
Fast, instant AU to SPEEX conversion. No signup required. Just drop your .au file and get .spx in seconds.
Batch Settings
在音频文件转换的众多需求中，AU格式与SPX格式的转换常常出现在特定场景。AU，作为Sun Microsystems早期广泛使用的音频标准，在一些传统系统或专业音频处理软件中仍有其身影。而SPX，即Speex，则以其专为语音优化而设计、兼顾压缩率和音质的特点，在网络通讯和移动应用领域占据一席之地。当您需要将那些经典或特定来源的AU音频，转换为更适应现代网络传输、分享或存储的SPX格式时，我们提供的工具将助您一臂之力。无论是为了节省宝贵的存储空间，还是为了在带宽有限的环境下实现更流畅的语音体验，抑或是为您的项目适配最新的音频标准，这次转换都将变得简单高效。
- 微信语音传输优化
- 游戏内语音包压缩
- 老旧音频资料归档
考虑到中国大陆、台湾及新加坡的用户习惯，SPX格式在移动社交和在线会议中的应用日益广泛，尤其是在追求传输效率和节省流量的场景下。部分台湾地区的游戏社区，也会倾向于使用此类高压缩率的语音格式进行交流。
About AU to SPEEX Conversion
AU or SPX — which format should you use? The answer depends on your needs. Here's a quick breakdown.
AU is a widely used file format. It has common platform support. SPX is a widely used file format. It has common platform support.
So when should you convert AU to SPX? This conversion is ideal when you When you need a SPX file. This conversion helps you convert between formats quickly.
Converting AU to SPX maintains high quality with CocoConvert's optimised encoder settings.
If you've decided SPX is the right choice, CocoConvert makes the conversion effortless. Upload your .au file, pick SPX, and click Convert — done in seconds. The converter runs on secure servers in Germany, powered by FFmpeg, Sharp, and qpdf. Files are encrypted via TLS and erased within 24 hours.
Free tier: 5 files/hour, 250 MB each. Pro: 100 files/hour, 5 GB each. Works in every modern browser on desktop and mobile.
How to Convert AU to SPEEX
- 1
Choose your AU file
Upload your .au file using drag-and-drop or the file browser. Batch mode lets you add multiple files.
- 2
Set format to SPX
Select .spx from the output options. The converter applies optimal quality settings automatically.
- 3
Run the conversion
Click Convert. Server-side processing means your device stays fast — even for large audio files.
- 4
Get your SPX file
Download your converted file instantly. Batch downloads are available as a zip archive.
What Happens When You Convert AU to SPEEX
Your AU file is decoded and re-encoded as SPX.
Your AU file is uploaded and validated
The file is decoded (parsed into its raw data)
The data is re-encoded in SPX format
The converted file is ready for download
Format Comparison
AU
.au file
| Extension | .au |
| MIME Type | audio/basic |
| Category | Audio |
Speex
.spx file
| Extension | .spx |
| MIME Type | audio/ogg |
| Category | Audio |
Should You Convert AU to SPEEX?
When to Convert
- ✓When you need a SPX file
Frequently Asked Questions
Should I use AU or SPX?
It depends on your goal. AU preserves full quality. SPX preserves full quality. Choose based on whether file size or quality matters more for your use case.
Is SPX higher quality than AU?
Not necessarily. Converting AU to SPX maintains high quality with CocoConvert's optimised encoder settings. Quality depends on the compression type and settings, not just the format name.
Can I convert AU to SPX on Mac and Windows?
Yes. CocoConvert is a web-based tool that works in all modern browsers — Chrome, Safari, Firefox, Edge — on any operating system including macOS, Windows, Linux, iOS, and Android.
Is CocoConvert free for AU to SPX?
Yes. Free users get 5 conversions per hour (250 MB each). Pro subscribers unlock 100 files per hour, 5 GB per file, and priority processing.
What tools does CocoConvert use for AU to SPX?
CocoConvert uses FFmpeg for audio/video, Sharp for images, and qpdf for documents — the same open-source libraries used by Netflix, YouTube, and major enterprise platforms.
Versions are pinned in our worker Dockerfile and re-built via CI on every change.