Figuring out sideloading on the updated Kindle for iOS app

Updated 12 Jan 2010 with corrections.

It turns out that the best new feature of the updated Kindle app…

After hearing back from others as well as from an Amazon developer, I re-tested all of my files on both an iPhone 3GS and an iPad, after restarting both of them, and the problems are nowhere near as big as I originally thought. I apologize for being an alarmist.

Here is an updated, and what I hope is more accurate, report on what to expect when sideloading Kindle format files.

MOBI format – Should work fine, so long as there’s no DRM protection on the file–and that should always be the case with .mobi because it’s not an official Amazon Kindle Store format. (You’ll find it on sites like Project Gutenberg and Feedbooks.)

AZW format – It depends on whether or not the file has DRM applied to it. If the file does not have DRM, even if it’s from the Amazon Kindle Store, it should open normally. If it has DRM, it should appear in your Kindle app library but will not open. (The app will tell you to delete the file and redownload it properly from your archive.)

Large files (above 1 MB) – These are tricky, but it appears the problem isn’t with Kindle but with Apple. The Mail app on iOS automatically downloads smaller attachments and recognizes when they’re Kindle files. On larger attachments, the Mail app won’t download them unless you tap the attachment image. In my tests, Mail refused to download these larger files because it didn’t recognize that they were Kindle formatted. Instead, it returned the error, “Mail cannot open this attachment.”

I got a similar error when trying to open larger .azw files from a webmail interface in Mobile Safari. However, I was able to successfully sideload these larger files via the Dropbox app, and I was able to add them via iTunes File Sharing when I connected my devices to my PC.

My advice: if you’re having weird issues that don’t align with what I just listed, manually quit the Kindle app (double-tap the Home button, then press and hold on the Kindle icon that pops up until you get a red quit button) and then restart your device. That seemed to clear up the issues I reported yesterday.

Thanks to Devini for the heads up!

(Photo: victorinox samoflange)