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Need help?Convert M4B to M4R: A Line from an Audiobook as Your Ringtone
M4B is the audiobook flavour of MPEG-4 audio. The audio inside is usually AAC, the container is the same one M4A and M4R use, and the .m4b extension tells Apple Books and other players to treat the file as a book: remember the listening position, show chapters, keep it out of the music library. That makes an audiobook a natural source for a spoken ringtone, whether it is a favourite line of narration, a narrator's famous opening, or a clip from an audiobook or podcast you recorded yourself. What it is not is short. This page lets you pick the 30 seconds you want out of a multi-hour file and saves them as an M4R, the file type iPhone uses for custom ringtones.
How to Convert M4B to M4R
- Upload Your M4B File: Drag the
.m4bonto the page or click "+ Add Files". The whole file is uploaded even if you keep only a few seconds, so a long book takes a while on a slow connection. - Choose a Bitrate: AAC is the only codec for M4R. Under File Compression, pick Constant Bitrate (8-384 kbps), one of the five Variable Bitrate bands (20k-32k up to 96k-112k), or a Custom Bitrate; Quality Preset leaves the exact rate to the encoder. For narration, 64-96 kbps is plenty.
- Trim to the Passage You Want: Under Trim, enter the Start time in HH:MM:SS.sss, for example 02:14:30.000, and a Duration of 30 seconds or less. Apple says iPhone ringtones can be up to 30 seconds long, and the note under Duration repeats that. Audio Channel can stay on Original, or use Mono for a single narrator.
- Convert and Download: Click Convert and save the
.m4r. Files travel over TLS, are processed on our servers and are deleted automatically after a few hours. Free, no sign-up, no watermark.
Finding the Right Timestamp
The Trim Start time is measured from the beginning of the whole file, not from the start of a chapter. That catches people out, because many audiobook players show elapsed time within the current chapter. Before you upload, find the line in your player and work out its position in the book as a whole. A player or editor that shows the total elapsed time makes this easy; otherwise add up the lengths of the earlier chapters.
Once you have the time, give yourself a little margin. Start a second or two before the line and set the Duration a few seconds longer than you need, then check the result. If it is not quite right, change the numbers and convert again: only the trimmed section is encoded, so each attempt is quick once the file is uploaded. For fine adjustments to an M4R you have already made, Trim M4R lets you drag the start and end on a waveform.
Why Not Just Rename .m4b to .m4r?
Because M4B and M4R are the same kind of file, renaming does change how the phone labels it, but it does nothing about the length. You would be handing iOS a ten-hour "ringtone". Apple's guidance is 30 seconds, and the point of this page is the Trim step. Converting also writes a fresh AAC-LC stream into an MPEG-4 file; ffprobe reports the result as AAC LC with the major brand M4A , exactly like an M4A. (The reverse route, M4R to M4B, exists too, though few people need it.)
M4B vs M4R at a Glance
| Property | M4B | M4R |
|---|---|---|
| Container | MPEG-4 | MPEG-4 (the same family as M4A) |
| Audio | Usually AAC | AAC (AAC-LC) |
| What the extension signals | Audiobook: bookmarking, chapters | Ringtone or text tone |
| Typical length | Hours | Up to 30 seconds, per Apple |
| Chapters | Common | Not needed for a 30-second clip |
| DRM | Common on store purchases | Must be DRM-free |
| Where it ends up | Apple Books, audiobook players | Settings > Sounds & Haptics on iPhone |
Which Audiobooks Will Convert
| Source | Converts here? | Notes |
|---|---|---|
| Audiobook you narrated or produced | Yes | The cleanest source |
| Public-domain recordings, such as LibriVox's, many of which are offered as M4B | Yes | Free to use as a tone |
| DRM-free purchases | Yes | Check the store says DRM-free |
| Apple Books or iTunes Store audiobook purchases | Usually no | Typically protected with FairPlay |
| Audible titles | No | Delivered as protected AA/AAX files, not M4B |
For a 30-second narration tone, 64 kbps comes to about 240 KB and 96 kbps to about 360 KB (AAC kbps multiplied by seconds and divided by 8).
From File to Ringtone
Copy the .m4r to the phone by one of the usual routes: on a Mac (macOS Catalina or later), connect the iPhone, select it in the Finder sidebar and drag the file onto it; on Windows, use iTunes; or, on the iPhone itself, save the file to Files, import it into GarageBand and choose Share > Ringtone, the route Apple documents. GarageBand only accepts audio that is not DRM-protected. Then pick the tone in Settings > Sounds & Haptics > Ringtone, or for a single caller via Contacts > the person > Edit > Ringtone.
Frequently Asked Questions
Can I convert an audiobook I bought from Apple Books or Audible?
Generally not. Store audiobooks are usually protected with DRM (FairPlay for Apple, a proprietary scheme for Audible's AA and AAX files), which encrypts the audio so it plays only in the authorised app. No converter here can read it. Your own recordings, public-domain books and DRM-free purchases convert normally.
Why is my clip starting in the wrong place?
Most likely because the Start time was taken from a chapter-relative clock. The Trim Start is counted from the very beginning of the file. Work out the position in the whole book and enter that, in HH:MM:SS.sss.
Do I have to upload the entire audiobook?
Yes. The whole file is uploaded, then only the trimmed section is encoded. If the book is very large and your connection is slow, it can be quicker to cut the passage out in an audio editor first and upload that.
What bitrate works for narration?
64-96 kbps is ample for a single voice through a phone speaker; set Audio Channel to Mono if the narration is mono anyway. If the clip includes music or sound design, 128-192 kbps keeps it clean.
How long can the ringtone be?
Up to 30 seconds, according to Apple's support article on custom ringtones; GarageBand shortens longer ones on export. A 40-second limit is widely quoted from the iTunes era but is not in Apple's current documentation.
Will the chapter markers or cover art come along?
Do not count on either. A 30-second ringtone has no use for chapters, and the iPhone's ringtone list shows the tone by name, so treat the M4R as audio only and keep the original M4B for listening.
What about Android, or a normal audio file?
Android does not use M4R; its ringtones are usually MP3 or OGG, so use M4B to MP3. To turn the audiobook into a regular music-library file instead, use M4B to M4A. Every route into M4R is listed on the M4R converter.
What happens to my file?
It is uploaded over an encrypted (TLS) connection, converted on our servers and deleted automatically after a few hours. Nothing is shared or published.