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Vmurph · 05-15-2014, 08:59 PM

I didn't post this question in the Calibre forum because it's not really about Calibre. The question is about conversion in general and my confusion about ePubs and Mobi files.

I was just fiddling around with Calibre, experimenting with different conversions and I noticed that converting mobi to mobi reduces the file size dramatically.

I started with a 3MB ePub (retail version) and converted it to mobi, and the mobi file was a little bit smaller, 2MB. But then I converted the MOBI to MOBI and the file size went from 2MB way down to 489K.

That's only a quarter of it's original size. What causes that kind of size difference? I'm guessing some data is stripped or altered during the process?

Just curious...

1.) What exactly occurs when a Mobi book is converted to Mobi? What is being changed?

2.) What happens to the file (content) when an ePub is converted to Mobi?

.

05-15-2014, 08:59 PM	#1
Vmurph Cat Whisperer Posts: 239 Karma: 2490708 Join Date: Jan 2010 Location: (USA) In the Hall of the Mountain King Device: Kindles Oasis 3, Kindle Oasis 1, and iPhone XS Max	Why does mobi to mobi change file size? I didn't post this question in the Calibre forum because it's not really about Calibre. The question is about conversion in general and my confusion about ePubs and Mobi files. I was just fiddling around with Calibre, experimenting with different conversions and I noticed that converting mobi to mobi reduces the file size dramatically. I started with a 3MB ePub (retail version) and converted it to mobi, and the mobi file was a little bit smaller, 2MB. But then I converted the MOBI to MOBI and the file size went from 2MB way down to 489K. That's only a quarter of it's original size. What causes that kind of size difference? I'm guessing some data is stripped or altered during the process? Just curious... 1.) What exactly occurs when a Mobi book is converted to Mobi? What is being changed? 2.) What happens to the file (content) when an ePub is converted to Mobi? .