mobi - missing covers on Kindle? works when converted

va55ago · 11-04-2020, 07:20 AM

Hi,

I'm struggling with one thing - I've bought a bunch of books, and can download them in various formats. Since I'm using Kindle Voyage, I'm downloading them in *.mobi format so that I can send them directly to my kindle e-mail address.
When I do though, for 80% of those books, the cover does not appear when transferred to my Kindle.

I have raised the issue with the online store, and I know they're working on it - trying different approaches, but not much has changed.

I thought about trying to troubleshoot it myself. I've loaded those downloaded books to Calibre, and just converted them from *mobi to *mobi. Once done, I've send the new files to Kindle... and - all the covers are now visible in both Kindle Voyage (and Kindle for iPad). Unfortunately, the books also lost some spacing, minor formatting, etc., that I didn't really want to change.
I am now trying to figure out how to use Calibre to correct/re-embed the covers to the mobile files, without changing anything about it's structure. I've tried to "Save the book to device", I've tried editing the metadata and saving the same cover I've had to the same file - no luck.

Any ideas what I could do to fix it?
All I'd like to achieve is to re-embed the cover in a mobile file, without changing the book's layout/formatting.

pdurrant · 11-04-2020, 07:41 AM

It's usually not that the cover isn't in the file, it's that Amazon is ignoring it.

MOBI (old pre-KF8 format) will show a cover. AZW3 (KF8) will not. IIRC.

va55ago · 11-04-2020, 07:58 AM

The funny thing is I'm only working on *mobi files - not really azw3.
Somehow, when converting mobi->mobi, covers do appear. Without it, they don't. So I'm curious about the magic Calibre does to somehow make my Kindle show the cover, and whether I could trigger just that mechanism, without converting the whole file/contents.

jhowell · 11-04-2020, 08:56 AM

There are different types of MOBI files. A MOBI file that you obtain from a store other than Amazon is most likely a Master-MOBI produced using kindlegen. This MOBI contains both the old MOBI 7 format with limited formatting and the newer KF8 (azw3) format with more advanced formatting in the same file.

When you email that file to your Kindle, Amazon delivers only the KF8 part of the file to your device. This gives better formatting but no cover thumbnail.

By converting from MOBI to MOBI you are changing the Master-MOBI into MOBI 7. This has limited formatting, however the Kindle will automatically extract the cover thumbnail in that case.

There are multiple ways to have the better formatting of KF8 along with cover thumbnails, but those involve sideloading to the Kindle via USB instead of using the Kindle email address.

11-04-2020, 07:20 AM	#1
va55ago Junior Member Posts: 2 Karma: 10 Join Date: Nov 2020 Device: Kindle Voyage	mobi - missing covers on Kindle? works when converted Hi, I'm struggling with one thing - I've bought a bunch of books, and can download them in various formats. Since I'm using Kindle Voyage, I'm downloading them in .mobi format so that I can send them directly to my kindle e-mail address. When I do though, for 80% of those books, the cover does not appear when transferred to my Kindle. I have raised the issue with the online store, and I know they're working on it - trying different approaches, but not much has changed. I thought about trying to troubleshoot it myself. I've loaded those downloaded books to Calibre, and just converted them from mobi to *mobi. Once done, I've send the new files to Kindle... and - all the covers are now visible in both Kindle Voyage (and Kindle for iPad). Unfortunately, the books also lost some spacing, minor formatting, etc., that I didn't really want to change. I am now trying to figure out how to use Calibre to correct/re-embed the covers to the mobile files, without changing anything about it's structure. I've tried to "Save the book to device", I've tried editing the metadata and saving the same cover I've had to the same file - no luck. Any ideas what I could do to fix it? All I'd like to achieve is to re-embed the cover in a mobile file, without changing the book's layout/formatting.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Missing cover on mobi/azw3 converted from ePub	Isamilis	Amazon Kindle	3	05-20-2016 05:36 AM
Converted Kindle Book Cover is Missing, anybody solved it?	alfarhan	Conversion	1	02-07-2016 12:52 AM
Missing cover in epub converted to mobi?	ddenison	Kindle Formats	0	11-26-2012 01:35 PM
black (or missing ) covers on epub-mobi conversion	jgawne	Conversion	0	03-07-2012 01:48 PM
Missing covers with .mobi on Kindle 3	random66	Calibre	8	10-15-2010 04:21 PM

11-04-2020, 07:41 AM	#2
pdurrant The Grand Mouse 高貴的老鼠 Posts: 71,522 Karma: 306214458 Join Date: Jul 2007 Location: Norfolk, England Device: Kindle Voyage	It's usually not that the cover isn't in the file, it's that Amazon is ignoring it. MOBI (old pre-KF8 format) will show a cover. AZW3 (KF8) will not. IIRC.

11-04-2020, 07:58 AM	#3
va55ago Junior Member Posts: 2 Karma: 10 Join Date: Nov 2020 Device: Kindle Voyage	The funny thing is I'm only working on *mobi files - not really azw3. Somehow, when converting mobi->mobi, covers do appear. Without it, they don't. So I'm curious about the magic Calibre does to somehow make my Kindle show the cover, and whether I could trigger just that mechanism, without converting the whole file/contents.

11-04-2020, 08:56 AM	#4
jhowell Grand Sorcerer Posts: 6,501 Karma: 84500001 Join Date: Nov 2011 Location: Tampa Bay, Florida Device: Kindles	There are different types of MOBI files. A MOBI file that you obtain from a store other than Amazon is most likely a Master-MOBI produced using kindlegen. This MOBI contains both the old MOBI 7 format with limited formatting and the newer KF8 (azw3) format with more advanced formatting in the same file. When you email that file to your Kindle, Amazon delivers only the KF8 part of the file to your device. This gives better formatting but no cover thumbnail. By converting from MOBI to MOBI you are changing the Master-MOBI into MOBI 7. This has limited formatting, however the Kindle will automatically extract the cover thumbnail in that case. There are multiple ways to have the better formatting of KF8 along with cover thumbnails, but those involve sideloading to the Kindle via USB instead of using the Kindle email address.

Advert