Skip to main content

Did You Know Calibre Can Make Epub 3 eBooks?

I was working on the calibre 4.0 post this morning when I discovered a new calibre feature. Well, it’s not new so much as I hadn’t noticed it before.

It seems that in May 2018 calibre gained the ability to make Epub 3 files. This should really come as no surprise (the new version of Epub was bound to replace the old eventually) but I for one did not know, and I thought it was worth bringing to your attention.

You can find the conversion option in the "Epub output" tab in the conversion menu. It’s rather well hidden, yes, which is why I expect that no one is using this option.

While we are on the topic, what calibre feature do you think everyone should be using?

P.S. That reminds me, I should probably update my post on cool tricks for calibre.

Similar Articles


gbm October 6, 2019 um 4:14 pm

You can change a epub2 to epub3 by using the editor then "Tools–Update book internals".

Randy Lea October 6, 2019 um 11:04 pm

Is there a benefit for converting an ebook from EPUB to EPUB3?

Nate Hoffelder October 7, 2019 um 7:21 am

I can’t think of one for users, no.

EPUB3 Commenter October 7, 2019 um 9:54 pm

> Is there a benefit for converting an ebook from EPUB to EPUB3?

There are some advantages depending on your ereader, like better renderers.

For example, EPUB3 on a Kobo will use Nickel instead of the old RMSDK (EPUB2) engine. (Most other devices use Readium as their EPUB3 engine.)

On the surface, you would get better hyphenation, justification, and layout (similar to Kindle’s "Enhanced Typesetting").

Underneath the surface, EPUB3 allows books to take advantage of more HTML5 and CSS3. So there’s better support for Footnotes, Math, and marking Semantics (screen readers being able to navigate around more easily).

Although most of this probably wouldn’t be added by a simple EPUB2->EPUB3 Calibre conversion, you would need to have someone update the actual innards.

Nate Hoffelder October 8, 2019 um 9:29 pm

Thank you for the clarification!

Robert Nagle October 10, 2019 um 12:06 pm

Nate, you may not realize this, but almost all reading systems provided minimal support for epub3 almost immediately after the standard was released. (I.e., they all could read epub3 files). Support for the mandatory features like css media queries came pretty quickly too — whether they rendered the way they were supposed to is another matter.

Whether ebooks you roll up yourself need this support is unclear too. Maybe calibre will convert MS Word files with footnotes into the corrrect elements?

Write a Comment