HTK Won't Open? Convert to AU Instantly
Fast, instant HTK to AU conversion. No signup required. Just drop your .htk file and get .au in seconds.
Batch Settings
About HTK to AU Conversion
Dealing with a HTK file that won't open on your device? You're not alone — HTK compatibility issues are one of the most common reasons people search for a file converter. HTK is a widely used file format.
The fix is simple: convert your HTK to AU. AU is a widely used file format. This conversion lets you convert between formats quickly, solving the problem in seconds rather than hours of troubleshooting.
Converting HTK to AU maintains high quality with CocoConvert's optimised encoder settings.
CocoConvert processes your HTK file on secure servers in Germany — upload, convert, download. Your files are encrypted via TLS and automatically deleted within 24 hours. No account needed, no software to install, and it works on any device with a browser.
This conversion is ideal when you When you need a AU file.
The conversion engine behind CocoConvert uses FFmpeg, Sharp, and qpdf — the same open-source libraries trusted by Netflix, YouTube, and enterprise platforms. Pro users can batch convert up to 100 files at once.
How to Convert HTK to AU
- 1
Add your HTK file
Drag and drop your .htk file into the converter, or tap "Browse" to pick it from your device. Multiple files are supported for batch processing.
- 2
Pick AU output
Select .au as the target format. CocoConvert automatically applies the best quality settings for this conversion.
- 3
Start conversion
Hit the Convert button. The audio engine processes your file server-side — no CPU drain on your device.
- 4
Save your file
Once done, download your .au file. For batch jobs, download all at once as a zip.
What Happens When You Convert HTK to AU
Your HTK file is decoded and re-encoded as AU.
Your HTK file is uploaded and validated
The file is decoded (parsed into its raw data)
The data is re-encoded in AU format
The converted file is ready for download
Format Comparison
HTK
.htk file
| Extension | .htk |
| MIME Type | audio/x-htk |
| Category | Audio |
AU
.au file
| Extension | .au |
| MIME Type | audio/basic |
| Category | Audio |
Should You Convert HTK to AU?
When to Convert
- ✓When you need a AU file
Frequently Asked Questions
Why won't my HTK file open?
HTK files may not open if your device lacks the right codec or application. Converting to AU — a more widely supported format — usually resolves this. AU is a widely used file format.
Is it safe to convert HTK to AU online?
Yes. CocoConvert encrypts your file via TLS, processes it on isolated servers in Germany, and permanently deletes it within 24 hours. Your files are never shared or analysed.
Will I lose quality converting HTK to AU?
Converting HTK to AU maintains high quality with CocoConvert's optimised encoder settings. CocoConvert uses high-quality encoder defaults to preserve as much fidelity as possible.
How large can my HTK file be?
Free users can convert files up to 250 MB each. Pro users get a 5 GB limit per file, and Business API users have custom limits.
Can I convert HTK to AU on my phone?
Absolutely. CocoConvert works in any modern browser — iOS Safari, Android Chrome, and all desktop browsers. No app required.
Versions are pinned in our worker Dockerfile and re-built via CI on every change.