HTML to MOBI to ePUB?!?

Jarno · 07-02-2021, 12:22 AM

Hi guys,

Thanks for reading my first post.

I just wanted to ask some advice on to how to "publish" my book.

I have everything in HTML files, and I'm using some of my own software to convert it to MOBI. It actually works!!

I can view it in Kind Previewer 3 without too many problems.

I did all that some time ago, and now I found out that Amazon will drop the MOBI format in August (in favor of ePUB?).

So, I can see two ways forward:

1. Convert MOBI to ePUB
2. Or somehow import the HTML files, and generate an ePUB file

My book is fairly simple, and I like the idea of going from HTML straight to ePUB, but how does it work when I change some of my HTML files, will I then have to convert it all over again then?

Would you consider a conversion from MOBI to ePUB "safe"? Metadata, etc.

Any thoughts on this?

Kind regards,
Jarno

Jellby · 07-02-2021, 03:03 AM

If you could write your own HTML-to-MOBI converter, an HTML-to-EPUB converter should be a piece of cake (in case you don't want to use already existing software like Sigil or calibre). ePub is just a zipped collection of (X)HTML files, plus a couple of XML metadata files. Modifying the HTML in an ePUB is just a matter of replacing the zipped file inside.

If you don't have the original HTML files or you are concerned about the metadata, you could give calibre's ebook-convert a try. I haven't tried it myself, but I guess it'll be pretty decent.

PS. But I don't think Amazon will use ePub, they'll probably use some concoction like AZW3...

JSWolf · 07-02-2021, 04:57 AM

You are best to convert your HTML to ePub and then use that as the source for sending to Amazon. Going HTML > Mobi > ePub is the long way round for a shortcut.

Turtle91 · 07-02-2021, 07:40 AM

I agree with Jellby - If you have the original HTML files, just add them to Sigil (or Calibre). Using that software when you update the html files will automagically create the proper files for ePub. If you only have the mobi files, then use Calibre's convert option to change mobi->ePub, then use Sigil/Calibre to clean up or update.

I do remember hearing that you should NOT use a raw Calibre converted ePub to submit to kindle for some reason (I don't remember why), but if you clean it up and run epubcheck then it works fine. Hopefully someone else can fill in the details.

Welcome to MR!

jhowell · 07-02-2021, 10:31 AM

Quote:

Originally Posted by Jellby

PS. But I don't think Amazon will use ePub, they'll probably use some concoction like AZW3...

The issue is that Amazon will no longer be accepting MOBI files from publishers. Only EPUB, KPF, and DOC/DOCX are allowed to be submitted for publishing. See the thread MOBI support for reflowable files ending... for more information.

Amazon will themselves convert the publisher format into the various Kindle formats needed for Kindle apps and devices.

Quote:

Originally Posted by JSWolf

You are best to convert your HTML to ePub and then use that as the source for sending to Amazon. Going HTML > Mobi > ePub is the long way round for a shortcut.

I agree with the others that converting (really packaging) HTML to EPUB is the way to go.

If you start from MOBI you may be missing some of the formatting that was present in your original HTML files since MOBI only supports a subset of HTML 3 and any MOBI converter would have had to take that into account, unless your files were already HTML 3.

Packaging HTML into an EPUB is fairly easy, but keep in mind is that EPUB does not support everything that can be done in HTML and that Amazon's support for EPUB is not 100% complete. You should check Amazon's Kindle Publishing Guidelines to see which HTML features are supported and update your HTML files accordingly.

Notjohn · 07-03-2021, 11:10 AM

I have for years cleaned up Word docs as html files (most recently using NoteTab Pro) and pasting the html file into a new epub2 document on Sigil. I add a standard style sheet, link to it, and then split the epub into chapters. I've been uploading the epubs to Kindle Direct Publishing since 2012 and have never had a problem. I then add a cover and upload an otherwise identical epub to Draft2Digital. I've never fussed with the so-called "mobi" file.

Jarno · 07-05-2021, 03:02 AM

Hi guys,

I just wanted to say a quick "thank you" for all your suggestions, and encouragements.

After some toying around with the HTML to EPUB conversion, I was finally able to get something working in Calibre, and it was really cool to see my book as an EPUB.

I had no idea idea that epub is just a zip file with (X)HTML files. I was able to re-use a lot of files, etc. There are some issues I need to fix, but I think it will work.

I ran an online epub validator on it, which showed some interesting issues.

1. Mimetype file entry is missing or is not the first file in the archive.

Strange, because I insert it first (uncompressed), and it's definitely there.

2. Error while parsing file: value of attribute "id" is invalid; must be an XML name without colons

Okay, my bad. Some of my IDs start with a number. I will need to change that.

3. Error while parsing file: element "u" not allowed anywhere

Argh!! Now I have to replace <u> with something like <span class="u">, etc. That doesn't look good at all. Who came up with that idea?!?

Is this perhaps because my html files say they're xml? Should I remove that line?

This is what I have now:

<?xml version="1.0" encoding="UTF-8"?>
<html xmlns="http://www.w3.org/1999/xhtml">

(From a template I used)

4. Error while parsing file: element "img" missing required attribute "alt"

Sigh... Okay, no idea what I'm going to put in there yet.

---

I think all that is doable, and Calibre is displaying it properly already anyway.

I came across Draft2Digital before as well. That looks really promising.

Anyway, now you know how it went.

Kind regards,
Jarno

Jarno · 07-05-2021, 03:04 AM

Oh, and I lost my cover page. I will need to add another page for that...

DNSB · 07-05-2021, 11:53 AM

Quote:

Originally Posted by Jarno

4. Error while parsing file: element "img" missing required attribute "alt"

Sigh... Okay, no idea what I'm going to put in there yet.

---

At a minimum, alt="". I prefer to put something meaningful in there such as alt="Map of Nedersturm" for the benefit of those who are not able to see the map when using text to speech for example. There is quite a bit of information on epubs and accessibility available for a quick web search.

07-02-2021, 12:22 AM	#1
Jarno Junior Member Posts: 3 Karma: 10 Join Date: Jul 2021 Device: Kindle	HTML to MOBI to ePUB?!? Hi guys, Thanks for reading my first post. I just wanted to ask some advice on to how to "publish" my book. I have everything in HTML files, and I'm using some of my own software to convert it to MOBI. It actually works!! I can view it in Kind Previewer 3 without too many problems. I did all that some time ago, and now I found out that Amazon will drop the MOBI format in August (in favor of ePUB?). So, I can see two ways forward: 1. Convert MOBI to ePUB 2. Or somehow import the HTML files, and generate an ePUB file My book is fairly simple, and I like the idea of going from HTML straight to ePUB, but how does it work when I change some of my HTML files, will I then have to convert it all over again then? Would you consider a conversion from MOBI to ePUB "safe"? Metadata, etc. Any thoughts on this? Kind regards, Jarno

07-05-2021, 03:02 AM	#7
Jarno Junior Member Posts: 3 Karma: 10 Join Date: Jul 2021 Device: Kindle	Yay, it works... (sort of) Hi guys, I just wanted to say a quick "thank you" for all your suggestions, and encouragements. After some toying around with the HTML to EPUB conversion, I was finally able to get something working in Calibre, and it was really cool to see my book as an EPUB. I had no idea idea that epub is just a zip file with (X)HTML files. I was able to re-use a lot of files, etc. There are some issues I need to fix, but I think it will work. I ran an online epub validator on it, which showed some interesting issues. 1. Mimetype file entry is missing or is not the first file in the archive. Strange, because I insert it first (uncompressed), and it's definitely there. 2. Error while parsing file: value of attribute "id" is invalid; must be an XML name without colons Okay, my bad. Some of my IDs start with a number. I will need to change that. 3. Error while parsing file: element "u" not allowed anywhere Argh!! Now I have to replace <u> with something like <span class="u">, etc. That doesn't look good at all. Who came up with that idea?!? Is this perhaps because my html files say they're xml? Should I remove that line? This is what I have now: <?xml version="1.0" encoding="UTF-8"?> <html xmlns="http://www.w3.org/1999/xhtml"> (From a template I used) 4. Error while parsing file: element "img" missing required attribute "alt" Sigh... Okay, no idea what I'm going to put in there yet. --- I think all that is doable, and Calibre is displaying it properly already anyway. I came across Draft2Digital before as well. That looks really promising. Anyway, now you know how it went. Kind regards, Jarno

07-05-2021, 03:04 AM	#8
Jarno Junior Member Posts: 3 Karma: 10 Join Date: Jul 2021 Device: Kindle	P.S. Oh, and I lost my cover page. I will need to add another page for that...

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07-02-2021, 03:03 AM	#2
Jellby frumious Bandersnatch Posts: 7,516 Karma: 18512745 Join Date: Jan 2008 Location: Spaniard in Sweden Device: Cybook Orizon, Kobo Aura	If you could write your own HTML-to-MOBI converter, an HTML-to-EPUB converter should be a piece of cake (in case you don't want to use already existing software like Sigil or calibre). ePub is just a zipped collection of (X)HTML files, plus a couple of XML metadata files. Modifying the HTML in an ePUB is just a matter of replacing the zipped file inside. If you don't have the original HTML files or you are concerned about the metadata, you could give calibre's ebook-convert a try. I haven't tried it myself, but I guess it'll be pretty decent. PS. But I don't think Amazon will use ePub, they'll probably use some concoction like AZW3...

07-02-2021, 04:57 AM	#3
JSWolf Resident Curmudgeon Posts: 74,015 Karma: 129333114 Join Date: Nov 2006 Location: Roslindale, Massachusetts Device: Kobo Libra 2, Kobo Aura H2O, PRS-650, PRS-T1, nook STR, PW3	You are best to convert your HTML to ePub and then use that as the source for sending to Amazon. Going HTML > Mobi > ePub is the long way round for a shortcut.

07-02-2021, 07:40 AM	#4
Turtle91 A Hairy Wizard Posts: 3,095 Karma: 18727053 Join Date: Dec 2012 Location: Charleston, SC today Device: iPhone 11/X/6/iPad 1,2,Air & Air Pro/Surface Pro/Kindle PW & Fire	I agree with Jellby - If you have the original HTML files, just add them to Sigil (or Calibre). Using that software when you update the html files will automagically create the proper files for ePub. If you only have the mobi files, then use Calibre's convert option to change mobi->ePub, then use Sigil/Calibre to clean up or update. I do remember hearing that you should NOT use a raw Calibre converted ePub to submit to kindle for some reason (I don't remember why), but if you clean it up and run epubcheck then it works fine. Hopefully someone else can fill in the details. Welcome to MR!

07-03-2021, 11:10 AM	#6
Notjohn mostly an observer Posts: 1,515 Karma: 987654 Join Date: Dec 2012 Device: Kindle	I have for years cleaned up Word docs as html files (most recently using NoteTab Pro) and pasting the html file into a new epub2 document on Sigil. I add a standard style sheet, link to it, and then split the epub into chapters. I've been uploading the epubs to Kindle Direct Publishing since 2012 and have never had a problem. I then add a cover and upload an otherwise identical epub to Draft2Digital. I've never fussed with the so-called "mobi" file.