ebook file sizes

[TomK2]

Today's free ebook from Tor.com is "The Calculating Stars." I know, crazy timing since it was selected for an upcoming monthly read. However, can someone explain ebook file sizes to me? From Tor.com, the epub version is 2.8 MB. The mobi version is 6.8 MB

Yet when I download the epub version and convert it to mobi in calibre, it gives me 1.8 MB for the mobi file size.

Then when I back it up, my backup file says 1.4 MB for epub and 1.8 MB for mobi.

So, what is going on? What is being left out by downloading epub and converting to mobi, any particular features?

[Kateblue, 2nd star to the right and straight on til morning]

No idea! I know nothing about this. I feel that the rest of us do not either, or someone would have said something.

I've noticed this a few times, also, but as long as I have Kindle space, I cannot say that I really care . . .

[Art, Stay home, stay safe.]

TomK2 wrote: "Today's free ebook from Tor.com is "The Calculating Stars." I know, crazy timing since it was selected for an upcoming monthly read. However, can someone explain ebook file sizes to me? From Tor.co..."

Sorry, I must've missed this post during my move.

The difference depends on many things, which converter is used, what quality it converts to and how the images, if any are present, sized down.

You will not lose any of the text content, unless it is corrupted, but that is a rare occurrence.

[Art, Stay home, stay safe.]

As for the features lost in a conversion, many new books have features besides the title page and chapter lists, you may lose those hyperlink features if your converter just works on the text itself.

But once again, nothing dramatic will happen even in the worst case of a bad conversion, unless it somehow gets corrupted.

[TomK2]

I was thinking of downloading the large kindle file, and putting it on my kindle. The theory is that a kindle file has 3 different formats to make sure you get one that will work for your reader? Then I was going to see if only one format went onto my kindle or all 3?

[Kateblue, 2nd star to the right and straight on til morning]

I tried to read Illuminae on Kindle, and I later found out that half the content was missing. The book as beaucoup diagrams and stuff. No wonder I hated it and couldn't figure out what was going on!

I got it from the library, so it should have worked. I am SO glad I did not buy it.

[TomK2]

So, I downloaded the large 6.8 MB file from Tor. I sent it to my kindle by email. It arrived on my voyage as a trimmed down 997kb file. This seems to verify that the file you download for your kindle has multiple versions which results in a larger file size of your download, but not on your device. However, for the last month or two, when I email to my kindle a book originally downloaded in kindle format, it arrives on my Kindles without a cover displayed on the home page grid view.

So I delete the book from my amazon account, and I send the mobi version that I created from an epub version I downloaded and converted in Calibre. It arrives on my kindle with a cover correctly displayed on the grid view.

So, creating a mobi file from an epub version in calibre once again preserves the cover for display on my kindle grid view. But now, the file size on my kindle is nearly twice the size, at 1.8 MB. OK, I am not out of room on my kindle, so I can afford the 900K file size increase to have the cover the way I like it. But it being twice the size makes me wonder if there are two versions in the file, and one of them had the cover and the other did not? I do not believe the cover would double the file size.

Not that this kinda stuff is important, but I guess I am just the curious type.

[Art, Stay home, stay safe.]

TomK2 wrote: "So, I downloaded the large 6.8 MB file from Tor. I sent it to my kindle by email. It arrived on my voyage as a trimmed down 997kb file. This seems to verify that the file you download for your kind..."

What matters is the encryption any converter is using. Remember old sound files? .WAV used to be about ten times the size of MP3s. Unless your converter somehow messed up, the copy should be almost, even though the size if the file is not the same. Images get scaled up or down in resolution during a conversion, which results in the majority of cases of discrepancies. Free software sometimes has a cap on resolution, unlocked through a payment or a subscription.

Official conversions are safer nowadays but first ebooks were a gamble, with images getting lost, footnotes destroyed, etc.

[Allan]

Very similar to what compression of music files do, at least MP3's. They chop off the high & low frequencies, so the resulting file only has about 5% of the actual content of the WAV file. Using lossless compression (FLAC is one)j works great to save space. I'd assume that there are similar file compression options for e-reader files as well. I don't do many though, so it's not a big issue for me.

[Oleksandr, a.k.a. Acorn]

in 90% o cases for ebooks the difference is due to size of pictures (chiefly covers) and then due to some bad work on text (assume text in italic with each word separately selected)