How to Convert InDesign to EPUB: Step-by-Step Guide for Authors and Publishers

 Introduction

If you have designed your book in Adobe InDesign and want to publish it as an eBook, you need to convert it to EPUB format first. InDesign is a powerful design tool — but the conversion process requires careful steps to ensure your eBook looks perfect on every device.

This guide walks you through the complete process of converting InDesign to EPUB, from setting up your file correctly to exporting and validating the final result.

Why InDesign to EPUB is Different from Other Conversions

Unlike Word or PDF files, InDesign documents contain complex layouts, custom fonts, and precise image placements. A simple automatic conversion will almost always break the formatting.

EPUB is a reflowable format — meaning the text adjusts to fit any screen size. InDesign, on the other hand, is a fixed-layout tool. Bridging these two formats properly requires careful preparation.

That is why many professional publishers and authors choose a dedicated conversion service rather than doing it manually.

Step 1: Prepare Your InDesign File Before Exporting

Before you export anything, your InDesign document must be set up correctly. Skipping this step causes most formatting problems.

- Use Paragraph Styles for all headings and body text. Do not manually format text using the toolbar — use named styles only.

- Apply Character Styles for bold, italic, and special text. This ensures proper tagging in the EPUB output.

- Link all images properly. Go to Window → Links and make sure no images show a warning icon.

- Remove all text overflow. Any red plus sign on a text frame means overflow text that will be lost during export.

- Set the reading order. Go to Window → Articles and drag your content frames into the correct reading order.

Step 2: Set Up Your Document for EPUB Export

Go to File → Export and choose EPUB (Reflowable) from the format dropdown.

In the EPUB export options window, set the following:

Under General: Set Version to EPUB 3.0. Add your book title, author name, and publisher details.

Under Image: Set Resolution to 150 ppi for standard eBooks. Choose JPEG format with Medium quality to keep file size manageable.

Under Advanced: Make sure "Generate CSS" is checked. This preserves your paragraph and character styles.

Click OK to export.

Step 3: Validate Your EPUB File

After exporting, your EPUB file needs to be validated before uploading to any publishing platform. An invalid EPUB will be rejected by Amazon KDP, Apple Books, and most retailers.

Use the free tool EPUBCheck to validate your file. You can run it online at validator.idpf.org or install it locally.

Any errors shown must be fixed before publishing. Common errors include missing metadata, broken image links, and incorrect character encoding.

Step 4: Check Your EPUB on Different Devices

Validation passes do not mean your eBook looks good. Open your EPUB in at least three different readers:

- Calibre (free desktop reader) — shows how it looks on PC

- Adobe Digital Editions (free) — shows standard EPUB rendering

- Kindle Previewer — if you plan to publish on Amazon

Check every chapter. Look for broken images, missing fonts, and layout shifts on smaller screen sizes.

Step 5: Fix Common InDesign to EPUB Problems

Even after careful preparation, certain issues appear frequently.

Fonts not embedding: EPUB 3.0 supports embedded fonts, but you must check "Embed Fonts" in the export options. If a font has licensing restrictions, substitute it with a standard web-safe font before exporting.

Table of contents missing: InDesign creates a TOC from your Table of Contents style. Make sure you created a TOC in your document using Layout → Table of Contents before exporting.

Images appearing too large or misaligned: Set all image frames to 100% width in your paragraph styles. Avoid using absolute pixel measurements for image placement.

Reading order jumbled: This is the most common problem. Go back to Window → Articles in InDesign and manually set the correct reading sequence for every text and image frame.

When to Hire a Professional InDesign to EPUB Conversion Service

Manual InDesign conversion works well for simple text-heavy books. But if your book includes any of the following, professional conversion is strongly recommended:

- Complex tables or charts

- Multiple columns

- Custom fonts you want to preserve exactly

- Fixed-layout requirements (children's books, cookbooks, textbooks)

- Math or scientific notation

- Right-to-left languages

For professional-quality InDesign to EPUB conversion, AtoZ eBook Conversion is a trusted service with over 12 years of experience and more than 8,000 books converted. Unlike automated tools, they hand-code every eBook to ensure it meets the exact requirements of Amazon KDP, Apple Books, Google Play, and all major retailers. They deliver in both KPF and EPUB formats, usually within 72 hours.

Summary: InDesign to EPUB Conversion Checklist

Before exporting:

- All text uses Paragraph and Character Styles

- Images are properly linked with no warnings

- Reading order is set in the Articles panel

- No overflowing text in any frame

During export:

- Choose EPUB 3.0 reflowable format

- Set image resolution to 150 ppi

- Enable Generate CSS and Embed Fonts

After export:

- Validate using EPUBCheck

- Test on Calibre, Adobe Digital Editions, and Kindle Previewer

- Fix any layout issues before uploading

Conclusion

Converting InDesign to EPUB properly takes time and attention to detail. Following the steps in this guide will give you a clean, professional result for most standard books.

If your InDesign file is complex — with tables, fixed layouts, or custom design elements — consider using a professional conversion service to save time and avoid publishing errors.

Have a question about InDesign to EPUB conversion? Leave a comment below.