GSM Won't Open? Convert to AU Instantly
Fast, instant GSM to AU conversion. No signup required. Just drop your .gsm file and get .au in seconds.
Batch Settings
GSM形式の音声ファイルをAU形式へ変換。この一見シンプルな作業が、実は奥深い音の表現と互換性の世界への扉を開きます。ビジネスの場面で重要な会議の議事録を、より汎用性の高い形式で共有したい時。あるいは、趣味で制作した音声作品を、古くからのオーディオ環境でも確実に再生させたい時。はたまた、漫画やアニメのキャラクターボイスを、特定の編集ソフトウェアでスムーズに扱いたい時など、その用途は多岐にわたります。私たちは、ユーザーの皆様が直面する様々な課題に対し、最適なソリューションを提供することを目指しています。この変換が、単なるファイル形式の変更に留まらず、皆様のクリエイティブな活動やビジネスコミュニケーションをより豊かにする一助となれば幸いです。音の持つ可能性を最大限に引き出すため、ぜひ当社の変換ツールをご活用ください。
- アニメの音声素材互換性向上
- ビジネス会議録の汎用配信
- レトロゲームサウンドの解析
AU形式は、特にUNIX系のシステムや一部の古いオーディオ編集環境で根強く利用されており、日本国内でも特定のニッチな分野でその互換性が重宝されることがあります。
About GSM to AU Conversion
Dealing with a GSM file that won't open on your device? You're not alone — GSM compatibility issues are one of the most common reasons people search for a file converter. GSM is a widely used file format.
The fix is simple: convert your GSM 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 GSM to AU maintains high quality with CocoConvert's optimised encoder settings.
CocoConvert processes your GSM 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 GSM to AU
- 1
Add your GSM file
Drag and drop your .gsm 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 GSM to AU
Your GSM file is decoded and re-encoded as AU.
Your GSM 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
GSM
.gsm file
| Extension | .gsm |
| MIME Type | audio/gsm |
| Category | Audio |
AU
.au file
| Extension | .au |
| MIME Type | audio/basic |
| Category | Audio |
Should You Convert GSM to AU?
When to Convert
- ✓When you need a AU file
Frequently Asked Questions
Why won't my GSM file open?
GSM 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 GSM 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 GSM to AU?
Converting GSM 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 GSM 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 GSM 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.