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Comment by paxys | Hacker News Reader

I'm very confused about what file format(s) Kindle actually supports.

* They are dropping support for MOBI from their Send to Kindle website and apps.

* They are adding support for ePub in their Send to Kindle website and apps, but apparently they will be converted to Kindle format (MOBI? AZW?) under the hood.

* Several sites mention AZW3 as the official Kindle format. Is that the same as MOBI?

* It is unclear whether ePub and/or MOBI are natively supported by Kindle.

If I connect my Kindle and (1) drag an ePub to its local storage and (2) drag a MOBI to its local storage, will either of them work or not?

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Mobi and AZW3 (aka KF8) are both at their core Palm DB files. AZW3 are basically Mobi files for backwards compatibility purposes, with an added compiled ePub file for improved layout options. Kindles can read both formats, with newer Kindles using the HTML/CSS from AZW3 files.

As far as I know, the only options to get an ePub onto a Kindle convert to an AZW3 before putting sending it to the Kindle (or manually convert to a Mobi file before sideloading it). And those conversions aren't perfect, I've absolutely had technically correct ePubs end up as a confused mess when sent to a Kindle. Though, these days most publishers seem to be targeting whatever subset of ePubs Amazon supports in their conversion pipeline.

AZW3 is itself one of their "old" formats. Their new hotness is KFX which is some proprietary binary ever-shifting always-DRM'd even when "DRM-free" format. This is the only format that supports the enhanced typesetting feature. The best way I've found to get ePubs onto Kindles is to use Amazon's Kindlegen. It does the least damage.

For local storage just use Calibre and stop worrying about formats IMO.

Drag whatever into Calibre, press send to device, end of story.

I bought Code 2e from the MS press store just this week.

I downloaded the epub, Calibre converted it to mobi when I said to deliver to my 2014 Kindle. Looked kinda crappy.

Downloaded the mobi direct, sent it to the Kindle. Looks much better.

The conversions are not always quality.

Hmm i only do fiction on readers (kindle or tablet). I guess technical books with diagrams and fancy formatting like sidebars etc would be a problem.

Short of a software update, I don't imagine older Kindles would magically be able to read ePub files.

It sounds like sideloading a .mobi file will still work.

My paperwhite did an update a month or so ago around the time I started getting emails about this. It’s been nice not converting to .mobi before transferring (sorry Calibre, I don’t need you anymore) but there are still a few glitches reading the format, especially with special characters. Nothing too annoying.

My 4th generation Kindle from 2011 didn't get a software update.

I did a sideload of .mobi today after being rejected by email, no issues.

I downloaded send to kindle this weekend trying to upload file bigger than 25mb tgat I can’t send by gmail. It didn’t accept ePub. I ended by using calibre to send it as email

It supports exactly the format it needs to so that you can purchase DRM encumbered ebooks off Amazon. I hope that clears it up.

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