Nook as an ePub renderer: review

by Liza Daly

(There’s an updated post on the 1.1.0 firmware.)

This isn’t a full review of the device. In particular, I don’t cover purchasing books or reading PDB or PDF books at all. I was mainly interested in evaluating the Nook as a general-purpose ePub reader.

Adobe Mobile SDK

Like other e-ink devices, the Nook uses the Adobe Mobile SDK as its rendering system. This means that some of the same features and quirks found in Adobe Digital Editions and earlier e-ink devices like the Sony Reader should apply here.

However, I didn’t know whether the version of the Mobile SDK on the Nook would be any more recent or evolved than the ADE or Sony versions (I have a PRS-505). So I experimented with the ePub rendering in the way I would any new device.

Test set

As you might imagine I have a lot of ePub books lying around. I tried a variety of commercial and non-commercial books, some generated via InDesign or other automated processes, and some coded in XHTML/CSS by hand.

Library lending

The Boston Public Library subscribes to the OverDrive ebook offering and there are a number of titles in ePub format. I checked out a book, and when Digital Editions started up it discovered the Nook (connected via USB) and asked if it wanted to authorize it. I was then able to transfer the library book over with no issues.

It did take a minute to find the book on the device: books copied via ADE end up in My Documents rather than in the main B&N books list. Since it’s just a regular filesystem, I think many users will probably manually copy books into just one place to keep it simpler.

Nook filesystem

Top level filesystem on the Nook. Files uploaded via ADE end up in Digital Editions


Library book on the Nook. Hey, all the good books had holds on them.


The Nook comes with three fonts: two serif and one sans-serif. In most ePubs I tried, changing the font face had no effect.

The image is blurry but you can vaguely see that while I have the font set to Helvetica Neue (which is sans-serif), the title and text are still in the serif font.


In another book I was able to change the font to sans-serif, but it didn’t apply equally throughout the content. A subset of the text that had its own styling remained serif:


Click to enlarge; see “The experiences” at the beginning of the chapter.

Font size changes did work as expected.

General UI comments

Changes in the local filesystem aren’t auto-detected. When you add a new book via USB, you have to manually “check for updates” to see the changes.

Selecting a book only brings up a rudimentary metadata page. While this is the kind of thing a nerd like me wants to see, does anyone else really care about the filesystem location of the book?


Only after selecting “Read” from the touch screen do you get to the cover image.

Language support

One of the things I was really hoping would be improved in the Nook relative to other Mobile SDK-derived products was international character support. Unfortunately, that is no better than ADE or similar readers:


Frustratingly, the Chinese book shown above did display Chinese characters in the listing of my library. I’m assuming this is because the Android OS is perfectly capable of reading the UTF-8 characters and has a Chinese font on-board, but the Mobile SDK does not.

I also tried an Arabic book with an embedded font, and while the font is displayed, the book’s text does not run right-to-left, and the necessary ligatures aren’t rendered. This is the same behavior as ADE. (Stanza and web-based readers like Bookworm display this same book correctly.)

Rendering performance

Here’s where things really fell down for me. I tried an edition of The People of the Abyss by Jack London. Mike Cane used this book to demonstrate some problems with ADE’s rendering.

This is a complex ebook though by no means an extreme outlier. It is hand-coded, which means that it doesn’t have unnecessary auto-generated markup, and it’s valid.

Many ereaders that paginate only render chapters on request, rather than at book loading time. That’s a good practice; it lets users get reading as soon as possible, and defers boring loading messages as long as possible. The Nook seems to be no different. When toggling between chapters (not pages), the user will generally get a “Formatting” alert; my guess is that it’s laying out each page based on the current font settings and content. You get a similar message when adjusting font settings, which also requires re-rendering.


Somewhat unprofessionally, the loading messages often aren’t middle-aligned correctly.

In most books I tested, the re-formatting between chapters or font changes took between 4-5 seconds. That’s slightly longer than the Kindle 1 or Sony PRS-505, which are the two devices I have for comparison.

For this particular book, re-formatting a chapter or going to a new chapter took 30 seconds.

Chapter renders are cached, but only in memory. If you close a book and re-open it, you get the same “Formatting” message again, and it will take just as long as before, even if you haven’t changed any settings.

(Jumping ahead into the book via the table of contents and then going “back” to a chapter you haven’t read before triggers the long rendering process, but no loading message is displayed. It looks like the device just hangs.)

This book demonstrated the same issues that ADE did in Mike Cane’s original post, so I don’t believe that the CSS support is any different in the Nook.

Loading failures

I tried loading a number of O’Reilly Media titles that are valid and work on the Sony Reader and every other ePub device. The Nook only brought up the “Formatting” message, and then hung. Only a full restart would bring it back.

This is an extremely serious problem.

Edited Dec 12, 2009 to reflect independent confirmation of this.

Hardware comments

I actually like the hardware quite a bit. While I’m right-handed, I like holding my ereader in my left hand and being able to turn pages that way. I prefer the Kindle 1 button placement to later Kindle versions, and I really dislike the hard, awkwardly-positioned buttons on the Sony 505. The Nook’s are easy to operate with either hand and don’t suffer from the extreme “bump” sensitivity of the Kindle 1.

I also didn’t have nearly as much of a problem with the LCD touch screen as other reviewers. Yes, the scrolling is quite slow and inaccurate, but single touch operations were responsive. Generally I found the interface intuitive, but your mileage may vary.

My one big complaint with the hardware is the weight. In the course of just 15 minutes of holding it, my hand got tired. I’m not sure the LCD screen is worth the strain.


I imagine that the books purchased on the B&N store won’t show these issues (especially those that are PDB rather than ePub with full CSS). But one of the key advantages of the Nook over the Kindle is its ability to read ePub from other sources.

While many of the rendering limitations are the same as those on the PRS-505 (now over a year old), I don’t have the same expectations in a new, more expensive device. The lack of support for non-English languages and non-Roman scripts is totally unacceptable, especially when the device’s operating system already comes with that support.

I do hope that the language issues and especially the performance bugs are resolved quickly, as non-B&N publishers may get hit hard on returns for non-functional books that are absolutely valid and should work.