MMF to AMR — Format Comparison & Online Converter
Fast, instant MMF (SMAF) to AMR conversion. No signup required. Just drop your .mmf file and get .amr in seconds.
Batch Settings
大切なあの人の声、お気に入りのアニメのセリフ、あるいはビジネスでの重要なやり取り。MMF形式で保存されたそれらの音源を、携帯電話や古いデバイスでも手軽に再生できるAMR形式へ変換したいとお考えではありませんか？ 当社の変換ツールは、複雑な設定なしに、大切な音源データをAMR形式へとスムーズに移行させます。音質の劣化を最小限に抑えつつ、ファイルサイズを効率的に最適化。特に、限られたストレージ環境や、特定の再生環境でしか利用できない場合にその真価を発揮します。シンプルな操作で、あなたのデジタルライフをより豊かにするお手伝いをいたします。
- ガラケーでの着信音設定
- 古いICレコーダーの音声再生
- ビジネス会議の議事録共有
日本では、フィーチャーフォン（ガラケー）時代にMMFやAMR形式が着信音や音声メモとして広く利用されていました。そのため、当時のデータを現在のスマートフォンで再生したいという需要が根強く存在します。
About MMF (SMAF) to AMR Conversion
MMF and AMR (introduced 1999) are both audio formats, but they differ in important ways. MMF is a widely used file format. AMR is a speech-optimised audio codec used in mobile voice recordings.
When you convert MMF to AMR, the goal is to convert between formats quickly. Converting MMF to AMR maintains high quality with CocoConvert's optimised encoder settings. Understanding these technical differences helps you choose the right format for your workflow.
Your MMF file is decoded and re-encoded as AMR. The conversion involves 4 steps: (1) your mmf file is uploaded and validated, (2) the file is decoded (parsed into its raw data), (3) the data is re-encoded in amr format, (4) the converted file is ready for download.
CocoConvert's converter handles the entire pipeline server-side using FFmpeg, Sharp, and qpdf — battle-tested libraries used by streaming platforms and enterprise tools. Files are encrypted in transit and deleted within 24 hours.
This conversion is ideal when you When you need a AMR file. For the opposite direction, CocoConvert also supports AMR to MMF conversion.
How to Convert MMF (SMAF) to AMR
- 1
Upload .mmf file
Select your MMF file by dragging it to the upload zone or using the file picker. Batch upload is available for multiple files.
- 2
Choose .amr
Set AMR as the output format. The converter uses optimal settings based on the MMF→AMR conversion profile.
- 3
Convert
The server-side engine decodes your MMF file and re-encodes it as AMR. Processing time depends on file size and complexity.
- 4
Download result
Grab your converted .amr file. Multiple output files can be downloaded together.
What Happens When You Convert MMF (SMAF) to AMR
Your MMF file is decoded and re-encoded as AMR.
Your MMF file is uploaded and validated
The file is decoded (parsed into its raw data)
The data is re-encoded in AMR format
The converted file is ready for download
Format Comparison
MMF (SMAF)
.mmf file
| Extension | .mmf |
| MIME Type | audio/x-smaf |
| Category | Audio |
AMR
.amr file
| Extension | .amr |
| MIME Type | audio/amr |
| Category | Audio |
Should You Convert MMF (SMAF) to AMR?
When to Convert
- ✓When you need a AMR file
Frequently Asked Questions
What is the difference between MMF and AMR?
MMF is a widely used file format. AMR is a speech-optimised audio codec used in mobile voice recordings.
Does MMF to AMR conversion affect quality?
Converting MMF to AMR maintains high quality with CocoConvert's optimised encoder settings.
Which format has better compression, MMF or AMR?
MMF is a common audio format. AMR uses lossy compression. The better choice depends on whether you prioritize file size or quality.
How long does MMF to AMR conversion take?
Most conversions finish in seconds. Larger files or complex audio content may take 10–30 seconds. CocoConvert processes files in parallel for batch jobs.
Is MMF or AMR better for long-term storage?
Both formats use lossy compression, so consider keeping your original source file for long-term storage.
Versions are pinned in our worker Dockerfile and re-built via CI on every change.