Young Writers Club · Lesson 2
What is an
EPUB?
You planned your book in Lesson 1. Now meet the file that turns your words into a real e-book — one that works on Kindles, phones, and tablets everywhere. It's simpler than you think, and a little bit magic.
spoiler · an epub is secretly a tiny website in a costume
00 The one idea
An EPUB is a liquid book.
A paper book has fixed pages — the words can never move. An EPUB is different: the words flow like water to fit whatever screen they're poured into.
- Tiny phone? The words reflow into a skinny column.
- Big tablet? They spread out comfortably.
- Grandma can't see small print? She makes the letters huge — and your book just adjusts.
Say it fancyGrown-ups call this "reflowable text". You can just say: my book is liquid. 💧
01 Three ways a book can travel
Paper, PDF, EPUB — what's the difference?
📕
Paper
Real and lovely to hold. But heavy, and one copy = one reader.
📷
PDF
A photo of your book. Looks the same everywhere — but it can't stretch or shrink. Squished on phones.
💧
EPUB
The book itself, alive. Reflows on every screen, dark mode, resizable letters. This is what e-readers speak.
When to use whichPDF is great for a picture book you'll print (Lesson 1!). EPUB is best when your book is mostly words — chapter books, stories, novels.
02 X-ray vision
An EPUB is secretly a ZIP folder.
Here's the magic trick: rename my-book.epub to my-book.zip, unzip it, and look inside. It's just a tiny website wearing a book costume:
my-book.epub ← secretly a .zip!
├── mimetype ← shouts "I am a book!"
├── META-INF/
│ └── container.xml ← the "start here" sign
└── EPUB/
├── package.opf ← the passport (title + author = YOU)
├── nav.xhtml ← the table-of-contents map
├── chapter1.xhtml ← your words, as a webpage
└── cover.jpg ← your art
→
Try it — with a grown-up, download any free EPUB, rename it to .zip, and go exploring. You're now a book detective. 🔍
03 Why this is perfect for you
Your plan is already halfway there.
Remember the Markdown file from your Lesson 1 planner? Markdown turns into EPUB almost by itself.
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It's free. No printing costs, no paper — your book can travel the world for $0.
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It works everywhere: Kindle, Kobo, Apple Books, Google Play Books, library apps, phones.
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Fixing is easy. Found a typo after publishing? Fix the file, upload again. Try doing that with 500 printed copies!
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Every chapter heading in your file becomes a tap-able table of contents. Automatically.
✕
Avoid — thinking e-books are "not real books". Same story, same author (you), lighter backpack.
04 How to make one
Three free ways (grab a grown-up).
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Calibre — a free program. Drag your file in, click Convert, choose EPUB. Done.
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Pandoc — one magic spell typed into the computer:
$ pandoc my-book.md -o my-book.epub
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Your writing app — many (like Pages or Reedsy) have "Export as EPUB" built right in.
Then what?Amazon KDP, Kobo, and Apple Books all accept your EPUB file directly. That's the "doorbell" step from Lesson 1 — and now you know exactly what you're handing them.
05 The passport
Every book carries its own ID card.
Inside the EPUB is a little file called the package — like a passport. Librarians and bookstores read it before anything else. It must say:
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Title — your book's name
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Author — YOUR name (best line you'll ever type)
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Language — so e-readers know how to read it aloud
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Cover image — the face of your book. Tall rectangle, like a real book cover.
✕
Avoid — leaving the title as "Untitled" or the author as "Unknown". Thousands of real e-books make this mistake. Not yours.
06 Test like a pro
Open it before you send it.
Real authors always check their EPUB the way readers will see it. Open yours in Apple Books, Calibre, or the Kobo/Kindle app and check:
- Does the table of contents jump to the right chapters?
- Make the text giant, then tiny. Does everything still look good?
- Turn on dark mode. Still readable?
- Do all the pictures show up?
→
Pro fact — EPUBs don't have page numbers! The words reflow, so "page 10" on a phone isn't "page 10" on a tablet. E-readers use locations and percent read instead.
07 Author facts
Three things real authors know.
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Your story is yours the moment you write it. That's called copyright, and kids get it too — automatically. Nobody may copy your book without asking.
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ISBN = a book's phone number, so shops can find it. You don't need one to start — stores like Amazon give your e-book its own ID for free.
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EPUB is an open standard — no company owns it. It's built by people who want books to work for everyone, everywhere, forever. Your book joins that club.
Say it fancy"My work is protected by copyright, distributed as an open-standard EPUB." Watch the grown-ups blink. 😎
✓ Before you convert
The E-Book Checklist.
- My book is finished — planned, drafted, revised (Lesson 1!)
- I know EPUB = a liquid book that reflows on every screen
- My passport is filled in: title, author, language, cover
- Chapter headings are real headings, so the contents map builds itself
- I tested it: contents, giant text, dark mode, pictures
- I remembered: no page numbers — and that's fine
- A grown-up helped me upload it (KDP, Kobo, or Apple Books)
A whole book, lighter than a feather.
Missed the planning steps? Go back to Lesson 1 · How to Make a Real Book.