Generate EPUB and Kindle Book output

The EPUB format helps you to distribute content to mobile devices, eBook readers, and tablets. Adobe Digital Editions, Calibre, and the EPUB Reader plug-in with Mozilla Firefox are some EPUB readers.

Adobe Digital Editions reader software is free and can be downloaded from the Digital Editions product site.

EPUB resources

Read this article by Neil Perlin to get an overview of EPUB, RoboHelp’s support for EPUB, and some best practices.

For a list of top features of EPUB, see

For more information on the EPUB format, see

For guidelines for creating well-formed and well-formatted EPUB documents, refer to (Best Practices Guide in EPUB format).

See the blog Digital Editions for information about Digital Editions.

Generate eBook output

1)In the Single Source Layouts pod, double-click the eBook SSL.

2)In the General tab, set the following options:

eBook Format(s)

Select EPUB 3 or Kindle Book or both as the eBook format. If you select EPUB 3, RoboHelp generates a .epub file. For Kindle Book output , RoboHelp uses the KindleGen converter to convert EPUB 3 output to Kindle Format 8 and Mobi output.

note:    If the KindleGen converter is not available on your computer, download it from the link provided in the Kindle Book Generation dialog box.

Output Folder And File Name

Specifies a location and name for the output files. To choose a location for the output folder, click the browse button browsebut.png.

note:    You need not specify the extension with the file name. Based on the output selected, RoboHelp adds the extension.

Validate EPUB 3 Output

Set RoboHelp to validate the EPUB output using the standard EPUB validation tool Epub­Check. EpubCheck require Java Runtime 1.5 or above installed on the computer.

note:    If the EpubCheck.jar file is not available on your computer, download it from the link provided in the EPUB Validation dialog box. Validation messages are available only in English.

Show KindleGen Logs

Select to display the errors, warnings, and status messages generated by the KindleGen converter in the Output View pod.

3)In the Content tab, set the following options:

Table Of Contents

Select the TOC to be displayed in the generated output. See TOCs.


Select the index to be displayed in the generated output. See Indexes.


Select the glossary to be displayed in the generated output. See Glossaries.

Variable Set

Select a variable set to override the default variable set in the generated output. See User-defined variables.

Conditional Build Expression

If you have conditional tags in the project, click Define to specify conditional build expres­sions. See Conditional build tag expressions.

Apply To All Topics

Select this option to apply master pages or CSS at the project level:

Master Page

The selected master page overrides the settings of all the individual topics with or without a master page applied to them in the project. The CSS and layout of the master page override the CSS and appearance of all the topics. If the selected master page does not have a header or footer, no topic displays a header or footer irrespective of if it had one header or footer defined.


The master pages associated with individual topics become effective. The selected CSS over­rides all the topics and their CSS irrespective of whether they are associated with a master page or not.

See Applying a master page or CSS at the time of generation.

Embed Fonts

Select this option to embed the selected fonts into the eBook. Use this option , if you are creating content that includes uncommon fonts, or if you are using custom fonts that may not be available on the end-users’ environment.

Since the fonts will be included as part of the eBook output, the user experience will be uniform even if some users do not have the font installed.

When you check this option, the Embed Font dialog is displayed. In this dialog, you can choose to embed fonts that are currently included in your RoboHelp project. You can also choose embed system fonts that are not currently included.

Embed Fonts dialog



Click manage to open the Embed Fonts dialog to make changes to the currently embedded fonts.

Exclude Unreferenced Topics From Output

Select this option to exclude any topic that exists in the project but is not the default topic in the layout or is not referenced from the selected TOC, index, or browse sequence, or any refer­enced topic.

note:    RoboHelp displays the unreferenced topics that are excluded from the output in the Output View pod.

Table Of Contents Settings

Select Index, Glossary, or both to add an index and a glossary at the end of the TOC. By default, the index is placed before the glossary. Use the Up and Down buttons to reverse the order in which the index and the glossary are to be placed.

4)In the Meta Information tab, specify metadata to conform to the Open Packaging Format (OPF) specification:


A title for the output. By default, RoboHelp displays the project name.


(Optional) The name of the author. To specify multiple author names, use comma as the separator.


(Optional) The name of the entity responsible for making the output available, for example, the author or the organization.


(Optional) A statement about rights, for example, a copyright notice.


(Optional) A description of the content.

Publication Identifier

An identifier conforming to specifications such as ISBN.


The language in which the content is written. For information about the format, see Dublin Core Metadata Element Set.

Publish Date

(Optional) The date of publishing the output. Follow the format specified in Date and Time Formats.

Cover Image

(Optional) Specify the path for a JPG, JPEG, or PNG image that you want to use as the cover page of the eBook and the dimensions (use percentage values to allow browsers to optimize display for different-sized screens). You can also specify a GIF image. However, in the case of a GIF animation, only the first frame is used as the cover page.

note:    If you don’t specify a cover image, RoboHelp uses the first topic in the TOC as the cover page.

5)In the Meta Information tab, click Custom Metadata and specify additional EPUB 3-specific metadata in XML format. For more information on specifying Metadata for EPUB, refer to EPUB 3 specification for metadata.

For example, if you want to add the identifier type (ISBN, UUID, DOI, etc) for a Publication Identifier, you can use the XML format below:

<dc:identifier id="pub-id">urn:doi:10.1016/j.iheduc.2008.03.001</dc:identifier>

<meta refines="#pub-id" property="identifier-type" scheme="onix:codelist5">06</meta>

6)In the Optimization Settings tab, set the following options:

Convert Auto-sizing And Custom-sized Popups To Hyperlinks

Select this option to make sure that hyperlinks configured to display in auto-sizing or custom-sized pop-ups are converted to flat hyperlinks.

Convert Text-only Popups To Hyperlinks

Select this option to make sure that text-only pop-ups are converted to flat hyperlinks.

Convert Absolute Image Size To Relative Image Size

Select this option to convert the actual width and height of images into percentages.

Convert Absolute Table Size To Relative Table Size

Select this option to convert the actual width and height of tables into percentages.

7)Click Save And Generate.

Best practices

Keep the following best practices in mind as you prepare your content for EPUB output:

Do not use space characters in bookmarks; space characters cause validation errors.

Do not use Frameset elements in your content.


The following HTML elements/attributes are not supported in EPUB 3 and are removed from EPUB output:


Marquees (marquee tags are removed, but the content is displayed in the output)

Table cellpadding

Table cellspacing

Table center alignment; the table appears left-aligned in the output

September 30, 2016

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