Tuesday, February 21, 2012

iBooks can open EPUB 3 files

I almost used a much more provocative title: iBooks supports EPUB 3 but then we would have to have a complicated discussion about “What does ‘support’ mean?” and even, “What does ‘EPUB 3’ mean?”

Keep in mind, for example, that an EPUB 3 file is not required to include anything besides text and simple formatting, and might be nothing more than EPUB 2 content in an EPUB 3 shell. Such a file would be much less difficult to “support”.

And also remember that supporting some aspects of a file format does not necessarily imply support of the entire file format. The EPUB 3 format itself is pretty loose about requiring what conformant systems must support.

But, now with all those caveats out of the way, I'm happy to say that it's true that you can open the EPUB 3 sample files available from the IDPF with iBooks.

And those files aren't particularly complicated, or replete with EPUB 3 features, but I did notice some interesting things.

First, there are three EPUB 3 files to look at so far, Moby-Dick, Wasteland, and Creative Commons - A Shared Culture. Only Wasteland has a toc.ncx file. The Shared book has no table of contents at all. But Moby-Dick (created by Dave Cramer of Hachette) uses the new-fangled XHTML style TOC:


and iBooks displays it beautifully:

EPUB3 in iBooks

This is a big deal if you ask me, as I'm not relishing having to create two separate annoying TOC files, one for new systems and one for legacy ereaders.

The Shared book includes video and audio, and scripts to control them, but it seems like the only scripted enhancement that partially works is the play button (and it works much better in a non-scripted way).

Shared EPUB3 on iBooks with video

The Moby-Dick book includes media overlays, ostensibly for narrating the text, but they don't seem to work yet.

We're not there yet, but the fact that iBooks supports EPUB 3 in some fashion is at least a beginning. Now we can begin testing what is possible, what is supported, and what we can create.

Note that Readium, the IDPF encouraged extension for Google Chrome, also supports EPUB 3. It's definitely worth downloading and playing with.


  1. Infogrid Pacific also has an EPUB3 reader called Azardi, and has posted some test books as well, at http://infogridpacific.typepad.com/digitalpublishing/2012/01/azardi-81-released.html
    I haven't had a chance to check them out yet; perhaps next month.

  2. In my opinion one of the big problems of the EPUB3 specs is the different direction it takes regarding the requirements for reading systems. This inevitably leads into various partial implementations. I don't think we will see a reader that "licenses" EPUB3 before 2013.
    The changes of an EPUB2 file to minimal EPUB3 really are minor as you stated in your entry. But because of the extensive requirements and involved technologies I can completely understand vendors hold back their commitment to "EPUB3 support".

  3. I make a personal epub3 texting file, based in Moby-Dick of Dave Cramer and Siddharta of InfogridPacific.
    Open it in Azardi 8.1 is perfect.
    Open in iBooks is functional, but iBooks dont know the css file.

  4. In my test with ePub3 iBooks does not recognize the epub:switch element

  5. "And also remember that supporting some aspects of a file format does not necessarily imply support of the entire file format."

    Doesn't this defeat the purpose of a standard format?


More of my books