MobileRead Forums - View Single Post - Converting (Kobo) epubs to reduce file size?

jackie_w · 01-30-2014, 11:26 AM

It may well be because the html files in Kobo-style epubs (kepubs) are full of extra <span> tags, e.g. <span class="koboSpan" id="kobo.32.1">some paragraph text</span>. These wouldn't be removed by a calibre conversion as it is perfectly valid code. A long book may have many thousands of them, which adds up.

As theducks says, if you open one up you can see them. With a bit of fancy Regex search/replace all you may be able to remove them to turn the kepub back to a standard epub, but the risk of deleting actual book content makes this rather risky and I wouldn't recommend it.

Edit: The other likely suspects are embedded fonts and/or a lot of images.

01-30-2014, 11:26 AM	#3
jackie_w Grand Sorcerer Posts: 6,252 Karma: 16544692 Join Date: Sep 2009 Location: UK Device: ClaraHD, Forma, Libra2, Clara2E, LibraCol, PBTouchHD3	It may well be because the html files in Kobo-style epubs (kepubs) are full of extra <span> tags, e.g. <span class="koboSpan" id="kobo.32.1">some paragraph text</span>. These wouldn't be removed by a calibre conversion as it is perfectly valid code. A long book may have many thousands of them, which adds up. As theducks says, if you open one up you can see them. With a bit of fancy Regex search/replace all you may be able to remove them to turn the kepub back to a standard epub, but the risk of deleting actual book content makes this rather risky and I wouldn't recommend it. Edit: The other likely suspects are embedded fonts and/or a lot of images. Last edited by jackie_w; 01-30-2014 at 11:32 AM.