Is the epub-mobi/mobi-epub convertion "lossless"?

[tanteoma]

I used to read on my iphone so I had most of my ebooks as epubs. Then I got a kindle touch which I loved very much in the beginning. I also happened to have a lot of free time on hand a few months ago, so I converted all my books into mobi via calibre and later when my neatness fixation kicked in, I deleted the original epubs. Now I'm switching back to reading on iphone and want my epubs back again.

So my question is, how much does it lose to convert a file from epub to mobi and vice versa? Is it a lossless convertion or a lossy one? My books are mostly literary fiction without complicated diagrams or special characters and I don't mind the occasional screw-ups in format as long as I can understand the books. Should I just convert the mobi files back to epubs or would I be better advised to find and re-download those original epubs again?

Many thanks to you in advance!

[theducks]

Originally Posted by tanteoma

I used to read on my iphone so I had most of my ebooks as epubs. Then I got a kindle touch which I loved very much in the beginning. I also happened to have a lot of free time on hand a few months ago, so I converted all my books into mobi via calibre and later when my neatness fixation kicked in, I deleted the original epubs. Now I'm switching back to reading on iphone and want my epubs back again.

So my question is, how much does it lose to convert a file from epub to mobi and vice versa? Is it a lossless convertion or a lossy one? My books are mostly literary fiction without complicated diagrams or special characters and I don't mind the occasional screw-ups in format as long as I can understand the books. Should I just convert the mobi files back to epubs or would I be better advised to find and re-download those original epubs again?

Many thanks to you in advance!

Mobi is a subset of EPUB. So losses occur if Mobi does not support that feature. Note the loss may not be apparent as some features have a workaround, but converting back does not gain back the old way.

[wallcraft]

If you were happy with the Kindle ebooks, converting them to ePub will work well most of the time. This is particularly true on a small screen, where the extra capabilities of ePub are likely lost anyway.

If you don't care for the mobi to epub formatting of a particular ebook, you can always re-download the original.

[itimpi]

As a general rule you should assume that all conversions are "lossy", particularly with regard to formatting information.

[tanteoma]

Thanks, guys, for the speedy responses. I think now I kinda understand and will just re-convert my files into epubs, but will keep the originals from now on in case this happens again. I really didn't notice anything amiss when I was reading the converted mobi files on Kindle. Stanza on my iphone seems to force its own format on epubs anyway.

[FizzyWater]

I have some ePubs that won't convert to a new font style (from serif to san serif, for example) when I do an ePub-to-ePub conversion. If I convert them to Mobi, then back to ePub, it allows me to change the font style. But then I notice that all those nice page breaks for each chapter are gone...

Those are the two things I've noticed when converting back and forth...

[ElMiko]

@taneoma - There are certain indentation configurations that don't translate. If you create a hanging indent paragraph format in EPUB, it won't render correctly upon conversion to MOBI. I'm sure there are other examples...

[tanteoma]

Thank you very much for the additional information.

[frostschutz]

Originally Posted by tanteoma

I deleted the original epubs.

Best if you don't ever delete books for any reason. In fact quite the opposite you should make extra copies of them.

The only way to make sure that a conversion worked 100% is to proof read the entire book. It's always good to have another copy / original / old version to go back to just in case. Book files are not huge so it's not a problem to keep extra copies tucked away somewhere, plus extra copies on a backup disk, or CD-R, ... (every storage media dies sooner or later and then where will you be?)

[pdurrant]

If you can re-download the originals, I'd certainly advise doing that. Apart from anything else, your Kindle Touch and calibre now both support the KF8 format, which does a much better job of matching the formatting of ePubs. In addition, it's possible that some typos in some of the books may have been corrected since the last time you downloaded them.

tl;dr: Always keep and convert from the original format. Newer software will make a better job of any conversions in the future.

[cybmole]

Originally Posted by pdurrant

. In addition, it's possible that some typos in some of the books may have been corrected since the last time you downloaded them.

I thought that Amazon stored the version you originally bought, & that the only way to get later corrections was to explicitly complain/ask ( or go thru the hoops of unlock, convert to epub, fix it yourself, convert back to mobi... )

have they now improved on this - do you now automatically get any new/improved version on a re-download , and do they have any concept of version numbering to help with spotting updates?

anyone have a link to their policy ?

[AnemicOak]

No, they still email you when a book is updated I got one a few weeks ago. You can then reply to the email with "yes" or update it yourself from the "Available for update" view sort option on the manage your kindle page. I always check MYK every once in a while as I don't seem to always get the email that there's an update.

[wallcraft]

Originally Posted by cybmole

I thought that Amazon stored the version you originally bought, & that the only way to get later corrections was to explicitly complain/ask

Amazon does store the original, which you might want to stick with if you have annotations etcetera. Sometimes Amazon sends e-mail about updated versions, and they can also show up on the manage your Kindle page as an option to switch. This does not happen very frequently, but I have no idea if there are "minor" updates that don't get pushed to previous buyers.

If an ebook gets an entirely new ASIN, you are stuck with the old one.

[pdurrant]

Originally Posted by cybmole

I thought that Amazon stored the version you originally bought, & that the only way to get later corrections was to explicitly complain/ask ( or go thru the hoops of unlock, convert to epub, fix it yourself, convert back to mobi... )

have they now improved on this - do you now automatically get any new/improved version on a re-download , and do they have any concept of version numbering to help with spotting updates?

You might get an email notification from Amazon, and I think you can also manually check and choose to get the update.

But Amazon isn't the only ebook store. The OP bought ePubs originally.

[JSWolf]

Originally Posted by pdurrant

If you can re-download the originals, I'd certainly advise doing that. Apart from anything else, your Kindle Touch and calibre now both support the KF8 format, which does a much better job of matching the formatting of ePubs. In addition, it's possible that some typos in some of the books may have been corrected since the last time you downloaded them.

tl;dr: Always keep and convert from the original format. Newer software will make a better job of any conversions in the future.

But in firmware 5.1 for the Kindle Touch, the line height defaults to too large and there's no way to fix that without a firmware update as it's a bug in 5.1. I cannot say about 4.1 if the line height bug exists there for the Kindle Button (no Touch, no Keyboard, just a big blah button).