Audio conversion
Convert M4B to FLAC
M4B is the format most audiobooks and podcasts are packaged in, and FLAC is a lossless format built for music. To convert, open the M4B in a converter and export it as FLAC. Doing this on your own computer means the file never has to be uploaded, though converting won't restore any quality the M4B already lost.
All 2,748 conversions verified on macOS, Windows, and Linux against the shipping release, this one included. Every conversion runs entirely on your own computer.
- Extension
- .m4b
- Type
- Audio
- Typically
- Audiobooks, podcasts
- Compression
- Lossy
- Extension
- .flac
- Type
- Audio
- Typically
- Lossless music
Convert M4B to FLAC on your own computer. Nothing uploads.
One-time purchase, no subscription. 14 days to change your mind.
How to convert M4B to FLAC
- Open Morphjet and drag in the M4B audiobook or podcast you want to convert. Add one file or a whole folder at once.
- Choose FLAC as the output format.
- Convert. The FLAC file is written next to your original, and nothing leaves your machine.
M4B vs FLAC: what actually changes
| M4B | FLAC | |
|---|---|---|
| File size | Smaller, compressed for spoken word | Much larger, since FLAC can't shrink data that's already lossy |
| Quality | Lossy, some detail discarded when it was encoded | Lossless copy of the M4B, but it can't recover what the M4B already threw away |
| Chapters and bookmarks | Yes, keeps chapter markers and remembers your place | No, chapter markers and resume position are usually lost |
| Compatibility | Apple devices and audiobook apps | Music players and hi-fi equipment, though not all audiobook apps |
| Typical use | Audiobooks, podcasts | Lossless music archiving |
When to convert, and when not to
Convert M4B to FLAC when you need the audio in software or gear that expects a lossless format, such as a music library or audio editor that doesn't handle M4B well.
Keep the M4B if you rely on chapter navigation and resuming where you left off, since FLAC generally doesn't carry those audiobook features, and converting won't make the recording sound any better.
Why not just use an online converter?
Audiobook and podcast files are often long and personal, hours of something you were listening to. An online converter needs you to upload the whole thing to its server before handing back a FLAC, which for a long file can take a while and leaves a copy sitting somewhere you don't control. Converting on your own computer keeps the file exactly where it already is.
Questions
Does converting M4B to FLAC improve the sound quality?
No. FLAC is lossless, but it can only losslessly store whatever detail is already in the M4B, and the M4B already discarded some audio data when it was first compressed. Converting makes an exact copy of what's there, not a better version.
Will I lose chapters or my place in the audiobook?
Usually, yes. M4B stores chapter markers and remembers your playback position, and FLAC has no real equivalent for either, so most players will show one long track with no resume point.
Why would I convert an audiobook to FLAC at all?
Mostly compatibility. Some music software, hi-fi equipment, or audio editors expect FLAC and don't handle M4B well, so converting makes the file usable there even though it adds no quality.
Will the FLAC file be much bigger than the M4B?
Yes, often several times larger. FLAC stores the full waveform losslessly, so even a modest audiobook can turn into a large file.
Can I convert M4B to FLAC without uploading it anywhere?
Yes. A desktop app like Morphjet converts the file on your own computer, so it never has to leave your machine.
Morphjet runs this conversion and 2,747 others, all on your machine. Available now.
One-time purchase, no subscription. 14 days to change your mind.