Video Conversion
Convert MP4 to M4B Online — Free
Fast, free MP4 to M4B converter. No registration required.
またはインポート元
200万以上のファイル変換
数千人のユーザーに信頼されています
安全な転送
HTTPS暗号化アップロード
プライバシー優先
処理後にファイルを自動削除
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すぐに変換を開始
どこでも動作
あらゆるブラウザ、あらゆるデバイス
変換方法
1
Upload your .mp4 file by dragging it into the upload area or clicking to browse.
2
Choose your output settings. The default settings work great for most files.
3
Click Convert and download your .m4b file when it's ready.
MP4とは？
MP4 is the most widely used video container format. It stores video, audio, subtitles, and metadata. Compatible with virtually every device and platform, from smartphones to smart TVs.
形式の詳細
- 正式名称
- MPEG-4 Part 14
- 拡張子
- .mp4
主な特徴
- Universal compatibility
- Streaming support
- Small file sizes
- Hardware-accelerated playback
M4Bとは？
M4B is the MPEG-4 audiobook format used by Apple iTunes and many audiobook platforms. It supports chapter markers, bookmarking, and AAC compression for efficient audiobook delivery.
形式の詳細
- 正式名称
- MPEG-4 Audiobook
- 拡張子
- .m4b
主な特徴
- Chapter support
- Bookmark resume
- iTunes compatible
- AAC compression
MP4とM4Bの比較
| 特徴 | MP4 | M4B |
|---|---|---|
| 正式名称 | MPEG-4 Part 14 | MPEG-4 Audiobook |
| 拡張子 | .mp4 | .m4b |
| 最適な用途 | Universal compatibility | Chapter support |
よくある質問
The audio track is extracted from your MP4 file without re-encoding when possible, preserving the original quality. If format conversion is needed, we use optimized settings to minimize any loss.
Free users can process files up to 100MB. Pro users can extract audio from videos up to 2GB with priority processing.
Audio extraction is fast — most files complete in under 30 seconds. Our servers handle the processing, so it works on any device.
Yes. You can adjust bitrate, sample rate, and channels before conversion. Default settings preserve the original audio quality from your MP4 file.
Yes. Our converter runs entirely in your browser — no app needed. Upload your video, extract audio, and download on any device.