What digital books are and the main ways to make one

A digital book is text, images, and formatting packaged into a file that readers open on a screen — a phone, tablet, e-reader, or computer. The most common formats are PDF (which looks the same on any device), EPUB (which adjusts text size and layout to fit the screen), and formats specific to platforms like Amazon's Kindle.

You have three realistic paths: write and format the book yourself using free or paid software, use a template-based service that handles some formatting for you, or hire someone to do the design work. The choice depends on how much control you want, how much time you have, and whether you plan to sell the book or share it for free.

Most people who create a digital book start with a document they already have — a manuscript in Microsoft Word, Google Docs, or plain text. From there, the work is converting that document into a format readers can actually use, which means adding proper spacing, chapter breaks, a table of contents, and sometimes cover design.

Key Takeaways

  • PDF works for any device but doesn't adjust text size; EPUB reflows text to fit the screen and is better for novels and long-form reading.
  • Free tools like Google Docs, Calibre, and Canva can handle formatting and cover design without paying for software.
  • If you plan to sell through Amazon, Smashwords, or Draft2Digital, each platform has specific file requirements and formatting rules you need to follow.
  • A table of contents, proper chapter breaks, and consistent formatting matter more to readers than fancy design.
  • Testing your file on actual reading devices or apps before publishing catches problems that won't show up in your computer's preview.

Starting with your manuscript and choosing a format

Open the document you want to turn into a book. If it's in Microsoft Word, Google Docs, or any standard word processor, you're already in a usable starting point. The first step is cleaning it up: remove extra spaces between paragraphs, use consistent heading styles for chapter titles, and make sure you're using actual line breaks (Enter key) rather than multiple spaces to create gaps.

Decide whether you want PDF or EPUB. Choose PDF if your book has fixed layouts, lots of images positioned precisely, or if you're sharing it directly with people rather than selling it through a platform. Choose EPUB if you're writing a novel, memoir, or any book where readers should be able to change text size and the layout should adjust automatically. Most platforms that sell digital books accept both, but EPUB is the standard for e-readers.

If you're using Google Docs, you can export directly to PDF: go to File, then Download, then PDF Document. For EPUB, you'll need to use a conversion tool like Calibre (free, open-source software) or an online converter. Word documents can also be converted using Calibre or by saving as .docx and uploading to a conversion service.

Formatting your manuscript so it reads well

Proper formatting means readers can navigate your book and the text is easy to read. Start by setting up your styles: use Heading 1 for chapter titles, Heading 2 for section breaks within chapters, and Body Text for regular paragraphs. In Google Docs, click the Styles button on the toolbar; in Word, go to the Home tab and use the Styles panel on the right. Applying styles consistently means that when you convert to EPUB or PDF, the structure comes through correctly.

Add a table of contents if your book has chapters. In Google Docs, go to Insert, then Table of Contents, and choose a style. In Word, go to References, then Table of Contents. The software will automatically pull in all your headings and create clickable links. Readers use this to jump to chapters, so it matters even in a short book.

Check your spacing: one blank line between paragraphs is standard, not two or three. Remove any extra spaces at the beginning of paragraphs — use the indent feature instead if you want indented first lines. Make sure your font is readable: standard choices are Times New Roman, Calibri, or Georgia at 11 or 12 points. Avoid decorative fonts for body text; save those for your title page or chapter headings if you want them.

Creating a cover and title page

Your cover is the first thing readers see, and it matters whether you're selling the book or sharing it for free. You don't need to hire a designer. Canva (canva.com) has free templates specifically for book covers; search for "ebook cover" and choose a template that fits your book's genre. You can upload your own images, add text, and download the result as a PDF or image file.

For a simple approach, create a title page inside your document: put your book title, your name, and publication date on a blank page at the very beginning. Format the title in a larger font (24 to 36 points) and center it. This becomes the first page readers see when they open your digital book.

If you're selling through Amazon or another platform, they have specific cover size requirements — usually 1600 by 2400 pixels for Kindle. Check the platform's guidelines before you finalize your cover. If you're just sharing a PDF with friends or posting it free online, any size works as long as it looks good on a screen.

Converting your document to EPUB or PDF

For PDF, the easiest route is your word processor's export function. In Google Docs, File > Download > PDF Document. In Word, File > Save As, then choose PDF from the dropdown. Open the PDF in a reader app (Adobe Reader, Preview on Mac, or your browser) and check that chapter breaks, page breaks, and images are where you expect them.

For EPUB, download Calibre (calibre-ebook.com) — it's free and works on Windows, Mac, and Linux. Open Calibre, click Add Books, and select your Word document or PDF. Right-click the book and choose Convert Books. In the dialog that opens, set the output format to EPUB. Calibre will convert your document and create a file you can download. Open it in an EPUB reader (Apple Books, Google Play Books, or Kindle for Mac) to check the formatting.

If you prefer not to install software, use an online converter like CloudConvert or Zamzar: upload your document, choose EPUB as the output format, and download the result. These services are free for small files. The quality is usually good, though Calibre gives you more control if something goes wrong.

Testing your book before sharing or selling

Open your finished file on the actual devices your readers will use. If you created an EPUB, test it in Apple Books on an iPhone or iPad, in Kindle for Mac or Windows, and in a free app like Thorium Reader on your computer. If you created a PDF, open it in Adobe Reader and a web browser. Look for broken chapter links in the table of contents, images that didn't convert properly, text that's cut off at the edges, and spacing that looks wrong.

Read through at least the first chapter and one chapter from the middle. Catch typos and formatting problems now, before you publish. If you find issues, go back to your original document, fix them, and re-export. It's much easier to fix before publishing than after.

Ask a friend or family member to test it too. They'll catch things you've read past a hundred times and can tell you if the file opens smoothly on their device. If you're selling the book, this step is especially important — readers will leave reviews about formatting problems, and fixing them after the fact is harder than getting it right the first time.

Publishing your book on a platform or sharing it directly

If you want to sell your book, the main platforms are Amazon Kindle Direct Publishing (KDP), Smashwords, and Draft2Digital. Each has different file requirements and royalty rates. Amazon KDP accepts MOBI and PDF files and pays 35% or 70% royalties depending on price and exclusivity. Smashwords accepts EPUB and distributes to multiple stores. Draft2Digital also accepts EPUB and handles distribution. All three have detailed formatting guides on their websites.

If you're sharing your book for free, you can upload it to Project Gutenberg (if it's in the public domain), post it on your own website, or share the file directly via email or a service like Google Drive. You can also upload free books to Amazon KDP, Smashwords, and Draft2Digital — they don't require you to sell.

Before you publish anywhere, read the platform's terms of service. Some require you to grant them exclusive rights; others let you publish the same book in multiple places. Understand what you're agreeing to, especially around pricing, royalties, and whether you can take the book down later.

Frequently Asked Questions

What's the difference between MOBI and EPUB?

MOBI is Amazon's older format, now being phased out in favor of KF8 (Kindle Format 8). EPUB is the open standard used by most other e-readers and apps. If you're publishing on Amazon, they accept both but prefer EPUB now. For everything else, EPUB is the standard choice.

Can I use images and illustrations in my digital book?

Yes. Embed images directly into your document before converting to EPUB or PDF. Make sure image file sizes aren't too large — compress them to 72 DPI for screen reading. Test on an actual device to confirm images display correctly and don't break the layout.

Do I need an ISBN for a digital book?

No. ISBNs are for printed books and are optional even for those. If you're self-publishing digitally, you don't need one. Platforms like Amazon KDP assign their own identifiers. You only need an ISBN if you're printing physical copies or want to list your book in library catalogs.

How much does it cost to create a digital book?

It can be free. Google Docs, Calibre, and Canva are all free. If you want professional cover design or editing, you'll pay for that separately — cover design ranges from $50 to $500 depending on the designer, and editing costs vary widely. The software itself doesn't have to cost anything.

What if my book doesn't look right after conversion?

Go back to your original document and check your formatting: make sure you're using styles consistently, remove manual formatting like extra spaces, and check that images are properly embedded. Then re-export or re-convert. If the problem persists, try a different conversion tool — sometimes one works better than another for specific document types.