digital publishing reference
EPUB Export from InDesign — Some Basics
This essay is meant to be a useful summary of issues that InDesign users encounter in their first attempts to export a project or document to EPUB format.
In seeing many questions about the EPUB export process, I have noted that the same basic information often needs to be covered before the discussion can get to more specific, individual answers. This is an attempt to provide those basics in a coherent, compact form.
There is, of course, an Adobe Help page for EPUB export, but it is much more of a “button by button” settings reference than any useful overview of how it all works together. Some users may find it a useful “other half” to this summary.
Published Online December 2022
Updated Here February 2023
EPUB Export from InDesign — Some Basics
1 :: InDesign is an excellent platform for EPUB (and Kindle).
- There may be no better platform than InDesign for EPUB for author/designers who focus on content and book design over archaic "assembly from components" methods.
- Although InDesign does take a reasonable level of mastery for EPUB development, you generally do not need specialized EPUB or e-book tools.
- Some ability to write web styling code (CSS) can be handy.
Don't put too much stock in "expert opinions" that InDesign is unsuitable or that only specialized EPUB tools can do the job. Both assertions are long outdated.
2 :: There are two EPUB standards in use.
- EPUB 2 (2.01, 2.xx) is a legacy standard whose sole proper use is to match existing document sets. It is outdated and should not be used for new projects.
- EPUB 3 and its variants should be used exclusively for new projects. If there is an option, use the latest version (currently EPUB 3.2).
3 :: There are two very different EPUB formats.
- Fixed-page EPUB, also called FXL, uses complex code to replicate each page as it appears in the document and very much as it would appear in print. While novices often gravitate to this option as it seems simple and obvious, FXL is an outdated approach that is obsolete for any EPUB document that is not a "picture book" such as a children's book, graphic novel, or dense pictorial info source such as a repair or how-to manual or art book. Avoid using FXL unless it is absolutely necessary — it is not the easier or better choice in most cases.
- Reflowable EPUB has contents that are "liquid" and flow to fill the reader screen much like a web browser. This is the correct, modern, "native" mode for e-books and designers should master and appreciate the medium, not try to replicate print pages on a screen. Adapt your project to reflowable and learn the export methods — it's worth it!
If what you want is an exact electronic version of a document, use PDF intead. It's much easier, almost foolproof, and far more universally accessible than EPUB.
4 :: Much depends on the EPUB reader used, and they vary enormously.
EPUB depends on the exact reader selected by each user. There are many, and few adhere to the EPUB standard. This means that creating an EPUB document that displays identically for all users is very close to impossible, and creating one that is at least organized and readable for some majority of users is difficult.
Since you can't do anything about this situation (such as require readers to use a designated reader), there are two approaches.
- First, design and optimize your EPUB to display cleanly on one of the 'vanilla,' standards-compliant readers like Thorium Reader or Calibre Reader. This means users with non-standard, non-compliant readers may have problems with the book, but that's because they choose to. Standard readers are available for all platforms.
- Second, if your audience or market demands it, optimize the EPUB to display cleanly on a specific, non-compliant, proprietary reader. These include Kindle (not compatible with anything else), Apple's iBook reader ("improved" in the way Apple does things, making it noncompliant with many EPUB standard elements) and many other "improved" or "better" or "let's do it this way" e-book readers. This means all other readers may display the book with faults, or perhaps not in readable form. If you are lucky, you can optimize for a standard reader, then tweak for compliance on, say, iBooks without losing the basic reader performance — but expect to put in the work to achieve that.
5 :: InDesign documents for export to EPUB must be meticulously constructed.
- Even more so than usually demanded by InDesign practices, a complete set of Paragraph and Character styles must be defined and used , with no spot or override formatting. Content flow and organization must be simple and consistent. Sloppy layout and shortcuts that will print fine will result in a mess when exported to EPUB format.
- An EPUB document must be one single text flow. Content cannot be split up into multiple flows, articles or loose text frames. Many faults in EPUB documents trace to not having this "single document flow."
- All content that is not part of that single text flow must be anchored in that text flow. Simply pasting images and text blocks on pages, as you might for print, won't work. An image must be anchored to the end of the paragraph it is meant to follow. A TOC frame must be anchored to the end of a suitable paragraph such as the title or copyright. Any content that is not anchored will be dumped to the end of the document.
6 :: Some layout features work differently in EPUB.
- Reflowable EPUB does not export any page structure material such as headers, footers, or page numbers. (Reflowable EPUB essentially does not have pages, or can be seen to have just one page, broken into units by the reader as needed.)
- EPUB can be exported from multiple INDD files using the Book feature , but a single source file will often work better, and will avoid many export problems. Don't use the Book method unless you have to.
- Reflowable EPUB does not support footnotes well but there are several options for including them. The options and results depend on the EPUB reader in use.
- Endnotes in EPUB can be problematic even with careful practices. If you must use end notes, expect to spend time adjusting them and fixing faults until they work well on a subset of EPUB readers. Special note: End notes from imported Word documents are especially prone to problems.
7 :: Some Recommended Formatting Basics
- Use simple fonts in your source document and make sure they have Regular, Bold, Italic and Bold Italic faces. Don't use variable or adaptable fonts, and avoid fonts with additional faces like SemiBold or Black, as they will not be used or will sometimes be interpreted incorrectly by EPUB readers.
- Don't embed fonts. If you work at the CSS level, use only generic font specifications to let the reader handle the display. Forcing a font on EPUB readers is not a good practice, and embedding fonts bloats the file size and leads to many display and readability errors. You can do much with just serif and sans-serif variations of reader default fonts.
- Apply a defined paragraph style to every single paragraph. This is absolutely not optional.
- Apply a defined character style to every local override , including ones for bold and italic. Don't depend on spot formatting for bold and italic (it's not always reliable), and definitely not for font, color or size changes.
- Page breaks do not work in most EPUB readers. There are advanced techniques to use if you want, for example, chapter headings to start on a new reader page, but there is no inherent "next page" function.
- Tabs don't work in EPUB. At all. Replace all tabs in your source document with some functional equivalent. The only consistent way to horizontally structure text is with tables.
8 :: Other Useful Information
- InDesign has two separate layers of image management for EPUBs. There is a streamlined option in the EPUB export menu that will apply globally to all images in the document. There is also an individual setting option with a greatly expanded selection of format, scaling, positioning and export options, accessible by right-clicking on any image in the document. The individual settings will take precedence over the global ones, or can be disabled at the time of export in favor of a global setting. The individual setting method is a bit complex to use. (There's an expanded discussion of EPUB image management here.)
- An EPUB document is essentially a packaged web page , using HTML code and CSS style management. Keep that in mind if you have web design experience or understanding; it may help you grasp many aspects of EPUB development and management. (That's for reflowable EPUB; the code generated for FXL EPUB is so dense and convoluted that it is essentially beyond manipulation once exported.)
- CSS style coding can be used to control any one style in the document, or override and fine-tune all of them, by adding a CSS file to the export. This is an advanced technique but can get around many limitations of ID's export, and even used to create complete "dual format" documents that can be exported to PDF for print and EPUB for e-book use from the same file.
- TOCs can be managed to provide different in-text and dynamic (reader-based) versions. However, unless one is truly useful, in-text TOCs are deprecated for e-books. The dynamic TOC can be much longer (including subheadings, for example) and is easier and faster for users to access.