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AU Won't Open? Convert to 3GP Instantly

Fast, instant AU to 3GP conversion. No signup required. Just drop your .au file and get .3gp in seconds.

256-bit TLS encryptionFiles deleted in 24hNo signup required

お持ちのAUファイルを、携帯電話や特定のデバイスで広く再生可能な3GP形式へ変換するお手伝いをいたします。音声ファイルの互換性にお悩みの方や、特定の環境での再生をスムーズにしたいとお考えの方にとって、この変換ツールは非常に役立つでしょう。煩雑な設定は不要で、直感的な操作で手軽に変換が可能です。大切な音声コンテンツを、より多くの場面でご活用いただくための一歩として、ぜひ当社のサービスをご利用ください。クリアな音質を保ちつつ、ファイルサイズを最適化し、様々なシーンでの利用をサポートします。

  • ビジネス会議の音声記録をスマホで共有
  • アニメ・漫画関連イベントのボイスメモを保存
  • 縦書き表示対応のガラケー向け着信音作成

かつて主流だったAU形式は、日本の携帯電話文化に深く根付いていました。3GP形式への変換は、現代のスマートフォン環境での再生互換性を高める上で、特に旧来のデバイスで作成された音声資産の活用に繋がります。

About AU to 3GP Conversion

Dealing with a AU file that won't open on your device? You're not alone — AU compatibility issues are one of the most common reasons people search for a file converter. AU is a widely used file format.

The fix is simple: convert your AU to 3GP. 3GP is a mobile video format designed for small file sizes on cellular networks. This conversion lets you convert between formats quickly, solving the problem in seconds rather than hours of troubleshooting.

Converting AU to 3GP maintains high quality with CocoConvert's optimised encoder settings.

CocoConvert processes your AU 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 3GP 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 AU to 3GP

  1. 1

    Add your AU file

    Drag and drop your .au file into the converter, or tap "Browse" to pick it from your device. Multiple files are supported for batch processing.

  2. 2

    Pick 3GP output

    Select .3gp as the target format. CocoConvert automatically applies the best quality settings for this conversion.

  3. 3

    Start conversion

    Hit the Convert button. The audio engine processes your file server-side — no CPU drain on your device.

  4. 4

    Save your file

    Once done, download your .3gp file. For batch jobs, download all at once as a zip.

What Happens When You Convert AU to 3GP

Your AU file is decoded and re-encoded as 3GP.

1

Your AU file is uploaded and validated

2

The file is decoded (parsed into its raw data)

3

The data is re-encoded in 3GP format

4

The converted file is ready for download

Format Comparison

.au

AU

.au file

Extension.au
MIME Typeaudio/basic
CategoryAudio
.3gp

3GP

.3gp file

Extension.3gp
MIME Typevideo/3gpp
CategoryAudio

Should You Convert AU to 3GP?

When to Convert

  • When you need a 3GP file

Frequently Asked Questions

Why won't my AU file open?

AU files may not open if your device lacks the right codec or application. Converting to 3GP — a more widely supported format — usually resolves this. 3GP is a mobile video format designed for small file sizes on cellular networks.

Is it safe to convert AU to 3GP 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 AU to 3GP?

Converting AU to 3GP 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 AU 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 AU to 3GP on my phone?

Absolutely. CocoConvert works in any modern browser — iOS Safari, Android Chrome, and all desktop browsers. No app required.

Powered by — installed on our conversion workers
FFmpeg 8.1 (static)

Versions are pinned in our worker Dockerfile and re-built via CI on every change.