kindlegen plugin for Sigil

[Doitsu]

Originally Posted by Interrobang

Kindle Previewer does not support this file, which has either been created using an older
version of KindleGen or a third party application. We recommend using EPUB or DOCX
format directly for previewing and publishing your book on Kindle.

Unfortunately, this is a limitation of Kindle Previewer. Even though the file selection dialog allows you to select *.azw3 files, it'll refuse to open them.

It'll open .mobi files generated by the KindleGenQt plugin, but only if the Generate AZW3/MOBI7 and Don't add source files options aren't checked. (This'll create a dual mobi file with attached source files.)

However, if you open a dual mobi file with Kindle Previewer, it'll convert it to a .kpf file, which will take a couple of minutes.

If you want to preview the output files, right-click them and select Open with > The Calibre e-book viewer.

[exaltedwombat]

Is there any advantage in using the plugin over converting with Kindle Previewer? Particularly considering KDP now prefers EPUB sources?

[Interrobang]

So which plugin options and file extension is best for side-loading onto a Kindle?

Thanks

[Doitsu]

Originally Posted by exaltedwombat

Is there any advantage in using the plugin over converting with Kindle Previewer? Particularly considering KDP now prefers EPUB sources?

If you just want to check whether a book meets the Enhanced Typesetting requirements, you don't need to use the plugin. However, you can only export .kpf and .mobi7 files from Kindle Previewer.
I use it mostly for converting .epub files to .kfx files, which I sideload on my Kindle and my tablet devices.

Originally Posted by Interrobang

So which plugin options and file extension is best for side-loading onto a Kindle?

IMHO, .kfx files are best for sideloading because thanks to jhowell's excellent Calibre KFX Output plugin the output will be pretty much identical to what you'll get from Amazon.
However, you don't need to use the KindleGen plugin for this, because you can also convert your .epub books to .kfx books with Calibre and send them to your device.

[LuQQ]

This plugin is awesome.