Audio Conversion
Convert AAC to M4B Online — Free
Fast, free AAC to M4B converter. No registration required.
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How to Convert
1
Upload your .aac 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.
What is AAC?
AAC is an audio coding standard designed to be the successor of MP3. It provides better sound quality at similar bit rates.
Format Details
- Full Name
- Advanced Audio Coding
- Extension
- .aac
Key Features
- Superior to MP3
- Streaming optimized
- Wide support
- Efficient compression
What is M4B?
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.
Format Details
- Full Name
- MPEG-4 Audiobook
- Extension
- .m4b
Key Features
- Chapter support
- Bookmark resume
- iTunes compatible
- AAC compression
AAC vs M4B
| Feature | AAC | M4B |
|---|---|---|
| Full Name | Advanced Audio Coding | MPEG-4 Audiobook |
| Extension | .aac | .m4b |
| Best For | Superior to MP3 | Chapter support |
Frequently Asked Questions
Yes. You can convert up to 5 files per day completely free, with no watermark or registration required.
Most files convert in under 30 seconds. Larger files (over 500MB) may take 1-3 minutes.
No. Our converter uses optimized encoding settings by default to preserve the original quality.
Free users can convert files up to 100MB. Pro users can convert files up to 2GB.
Yes. Our converter works in any modern web browser on any device.