AudioBo: Add Chapters to Audiobooks From a Timestamp File

Here’s a scenario I suspect many of you know too well: you’ve got an audiobook — one long audio file, maybe 10 hours — and it plays fine, sounds great, but there are no chapters. Just one continuous blob from start to finish.

You know where the chapters should be. Maybe you found timestamps on YouTube. Maybe you have a CUE sheet from a CD rip. Maybe you just wrote them down yourself while listening.

Until now, turning that knowledge into actual chapters meant pain. Real pain. You’d need to open the file in Audacity or some other audio editor, manually split it at each timestamp, export each piece as a separate file, rename them all, then import them into an audiobook tool. For a 30-chapter book, that’s an afternoon you’re never getting back.

Starting with version 1.2.1, AudioBo now does all of that automatically. Give it your audio file and a text file with chapter timestamps — and it splits the book into chapters for you.

One audio file in. One chaptered audiobook out.

One related note: if you don’t already have a timestamp file, you might not need to make one by hand. AudioBo also has a Fetch Metadata feature that can look up audiobook details — and, in some cases, chapter titles and timing — from sources like Audible, Apple Books, and Google Books. So there are really two good paths now: bring your own sidecar file if you already have timestamps, or let AudioBo try to pull the book data from the internet if you don’t. I wrote more about that in AudioBo: Fetch Audiobook Metadata and Chapters from Audible, Apple Books, and Google Books.

The YouTube Chapters Format (Start Here)

This is the format I want you to know. It’s dead simple, and it’s probably exactly what you need.

Here’s how it works:

Step 1: Create a text file

Open any text editor — TextEdit, VS Code, whatever. Create a new file.

Step 2: Write your chapters, one per line

Each line is just a timestamp followed by the chapter title:

0:00 Introduction
5:30 Chapter 1 - The Beginning
15:45 Chapter 2 - The Journey
1:02:30 Chapter 3 - The Twist
1:45:00 Chapter 4 - Resolution
2:10:15 Epilogue

That’s it. Timestamp, space, title.

Step 3: Name the file to match your audiobook

This is important. If your audiobook is called MyAudiobook.mp3, name your chapter file MyAudiobook.txt.

MyAudiobook.mp3
MyAudiobook.txt       ← chapters go here

When the names match, AudioBo finds the chapter file automatically. You won’t even need to drag it — just import the audio, and the chapters appear.

Step 4: Put both files in the same folder

AudioBo looks for chapter files next to your audio. Same folder, matching name — that’s the recipe.

Step 5: Drag both audio files into AudioBo (or the entire folder)

AudioBo detects the chapter file, parses the timestamps, and applies them. Your 10-hour blob is now a properly chaptered audiobook.

Timestamp Formats That Work

AudioBo is flexible about how you write timestamps:

0:00 — minutes and seconds
00:00 — also fine
1:30:00 — hours, minutes, seconds
01:30:00 — with leading zero, also fine
1:30:00.500 — with milliseconds, if you’re precise
[0:00] or (0:00) — brackets or parentheses are stripped automatically
1. 0:00 Title — numbered lists work too

All of these are valid first lines:

0:00 Introduction
00:00 Introduction
[0:00] Introduction
1. 0:00 Introduction
0:00 - Introduction

AudioBo figures it out.

Where to Get Chapter Timestamps

If you’re wondering where to find timestamps in the first place:

YouTube — Many audiobook uploads have chapter markers. Click “Show more” in the description, copy the timestamps.
Audible screenshots — The chapter list is visible in the app. Type them out.
Goodreads or Wikipedia — Some books list chapter titles; you’ll need to find the timings yourself, but at least you have the structure.
Listen and note — Old school, but it works. Play the audiobook, jot down timestamps as chapters change.

Once you have the list, paste it into a text file, save it with the same name as your audio, and you’re done.

Other Formats (For Power Users)

The simple text format handles 90% of cases. But AudioBo also reads these professional formats if you have them:

Format	Extension	Where It Comes From
CUE Sheet	`.cue`	CD ripping software (EAC, XLD, foobar2000)
FFmpeg Metadata	`.ffmetadata`	`ffmpeg -f ffmetadata` exports
MKV Simple	`.txt`	MKVToolNix simple chapters
MKV XML	`.xml`	MKVToolNix full chapter export
MP4 Chapters	`.chapters.txt`	MP4Box, Subler
Audacity Labels	`.txt`	Audacity “Export Labels”

Same rules apply: name the file to match your audio, put it in the same folder. AudioBo detects the format automatically — you don’t pick from a dropdown.

How AudioBo Finds Your Chapter File

Let me be explicit about the matching logic, because it’s smarter than you might expect:

Best case — exact name match:

MyBook.mp3
MyBook.txt       ← found automatically, high confidence

Also works — common suffixes:

MyBook.mp3
MyBook.chapters.txt    ← found
MyBook_chapters.txt    ← found
MyBook-chapters.txt    ← found

Works if there’s only one of each:

Folder/
  audiobook.mp3
  chapters.txt         ← found (only one audio + one text file)

Multi-disc scenario:

CD1.flac + CD1.cue     ← matched
CD2.flac + CD2.cue     ← matched

The golden rule: name your chapter file the same as your audio file. Everything else is a fallback.

Multi-File Audiobooks

If your audiobook is already split into multiple files — say, one file per CD — AudioBo can match each file to its own chapter file:

CD1.mp3 + CD1.cue
CD2.mp3 + CD2.cue
CD3.mp3 + CD3.cue

Each disc gets its own chapters, applied independently.

But if you have multiple audio files and a single chapter file that spans all of them, AudioBo handles that too — timestamps get mapped across files based on cumulative duration.

Things to Know

First chapter starts at 0:00 — AudioBo expects your first chapter to begin at the start. If it’s off by a fraction of a second, it auto-corrects. If it’s way off, you’ll get an error.
Timestamps must be in order — Each chapter starts after the previous one. No jumping backwards.
Minimum chapter length — Chapters need to be at least 5 seconds long. Shorter than that gets flagged.
At least 2 chapters — A single chapter isn’t really a chapter list, is it?
File size limits — Chapter files max out at 1 MB, up to 500 chapters. If you’re hitting those limits, I have questions about your audiobook.

When You’ll Love This

The YouTube scenario: Someone posted your audiobook on YouTube with chapters in the description. Download the audio, copy the timestamps into a text file, drop both into AudioBo. Done.
The CD rip scenario: You ripped a multi-disc audiobook years ago. Each disc has a .cue file. Now you can turn those into a single chaptered M4B without touching an audio editor.
The “I know where the chapters are” scenario: You’ve listened to this audiobook before. You know roughly where each chapter starts. Jot down the timestamps while listening, save as a text file, import. Your single-file audiobook is now properly chaptered.

Try It Yourself

I’ve been using this feature for a few weeks, and I’m surprised how often I reach for it. I hope you will like it too! If you don’t have AudioBo yet and want to see the chapters in action — grab a demo version.