Linux ePub reader app that best fullfills the ePUB standard

celiapgt · 07-30-2021, 12:35 AM

Hi, everyone!

I'm trying to use an app for ePub reading in Linux that best fullfill the ePUB 2.x standard (I mean that I'm not interested in ePUB 3).

Which one do you recommend?

I always see so many differences between them with the same ePub file. I would love to know which is the most accurate to the fullfill the standard. I understand that no app does it completely. Maybe I am wrong.

I'm looking at something able to render ePub files as close to the ADE does because I was told by Windows users that ADE is the standard app (?).

Just to mention, I have tried KOReader, Foliate, ePUBReader, Calibre eReader, FBReader, CoolReader…

Thanks for your suggestions.

davidfor · 07-31-2021, 01:23 AM

Quote:

Originally Posted by celiapgt

Hi, everyone!

I'm trying to use an app for ePub reading in Linux that best fullfill the ePUB 2.x standard (I mean that I'm not interested in ePUB 3).

Which one do you recommend?

I always see so many differences between them with the same ePub file. I would love to know which is the most accurate to the fullfill the standard. I understand that no app does it completely. Maybe I am wrong.

This is largely because the standard is not very strict. It says things that are needed, but, leaves a lot open to interpretation. And a lot of it comes down to what they use for rendering. Exactly how they handle the rendering is different and hence the results are different.

There is also the fact that the ebook creators are not necessarily looking a the standards. Some are trying to force looks to match the paper books. Others are producing a version for Kindles and the epub is a side thought.

Quote:

I'm looking at something able to render ePub files as close to the ADE does because I was told by Windows users that ADE is the standard app (?).

Not really. I don't think I have ever seen a suggestion that people should actually read books using ADE. It is necessary for downloading epubs that have Adobe DRM. It is also suggested as a way to test books to get an idea whether they will work with ereader devices and apps that are based on the Adobe RMSDK. And the main reason for that is that these are not forgiving of errors in the books. For example, if you have an error in a stylesheet, anything based on the Adobe RMSDK will reject the complete stylesheet. But, using it as a your primary way of reading a book, no.

Quote:

Just to mention, I have tried KOReader, Foliate, ePUBReader, Calibre eReader, FBReader, CoolReader…

I can't help you there as I the only PC based ereader I have used recently is the calibre viewer. And I don't really think looking for a fully standards compliant app is useful. Or actually going to find something. You are probably better to look for the one that produces a result that you like. There is a lot of discussion about font rendering and whether the app shows ligatures and similar, how well they handle hyphenation, support for footnotes, etc. Then there is how they handle annotations and if they support syncing reading status and annotations. And how easy they are to use.

LinuxArie · 07-31-2021, 03:06 AM

Maybe these sites will help
https://linuxhint.com/best_linux_ebook_readers/
https://itsfoss.com/best-ebook-readers-linux/

JSWolf · 07-31-2021, 07:09 AM

I highly recommend installing Calibre and using the Calibre eBook viewer.

Tex2002ans · 08-01-2021, 06:11 PM

Quote:

Originally Posted by celiapgt

I'm trying to use an app for ePub reading in Linux that best fullfill the ePUB 2.x standard (I mean that I'm not interested in ePUB 3).

Which one do you recommend?

Thorium Reader is "decent" (and runs on all 3 major platforms):

https://www.edrlab.org/software/thorium-reader/

It's created by Readium, who is the company that designed the base EPUB3 renderer used by ADE (and others).

Quote:

Originally Posted by celiapgt

Just to mention, I have tried KOReader, Foliate, ePUBReader, Calibre eReader, FBReader, CoolReader…

Most of these are non-standards compliant. They work by completely overriding most/all of the book's CSS, mangling things like:

Negative indents in poetry
Scenebreaks that use a gap instead of something like * * *.
Embedded fonts for rare characters (like the 🌔 Gibbous Moon)

I wrote about this in more detail in 2020: "Colored Text, EPUB, Android Dark Mode" + 2019: "Epub-problems in tablets".

davidfor · 08-01-2021, 09:49 PM

Quote:

Originally Posted by Tex2002ans

Most of these are non-standards compliant. They work by completely overriding most/all of the book's CSS, mangling things like:

Negative indents in poetry
Scenebreaks that use a gap instead of something like * * *.
Embedded fonts for rare characters (like the 🌔 Gibbous Moon)

Does that include KOReader? I don't use it but see a lot of discussion about it as an alternative on Kobo ereaders. From that, I assumed it was doing at least as good a job as the RMSDK and Kobo's kepub renderer. Or does it have an option to ignore it and that is the default?

The same goes for the calibre viewer. I mainly use it for quick checks, but, it generally matches with what I see on my Kobo devices. It is possible to override a lot, but, I don't.

skillachie · 08-04-2021, 12:31 AM

Quote:

Originally Posted by celiapgt

Hi, everyone!

I'm trying to use an app for ePub reading in Linux that best fullfill the ePUB 2.x standard (I mean that I'm not interested in ePUB 3).

Which one do you recommend?

I always see so many differences between them with the same ePub file. I would love to know which is the most accurate to the fullfill the standard. I understand that no app does it completely. Maybe I am wrong.

I'm looking at something able to render ePub files as close to the ADE does because I was told by Windows users that ADE is the standard app (?).

Just to mention, I have tried KOReader, Foliate, ePUBReader, Calibre eReader, FBReader, CoolReader…

Thanks for your suggestions.

You could take the BookFusion Web app for a spin that will work on Linux and any other operating system. The bonus is that we also have native Android and iOS apps so you will be able to keep your highlights and reading progress synced across all devices.

We plan on having native Linux, OSX & Windows app by Q1 2022. More at https://www.bookfusion.com/reading

PS: Founder at BookFusion. Feel free to reply with feedback or DM.

Quoth · 08-07-2021, 06:00 AM

I think mangling in KOReader is sort of optional. You can set it that doesn't suck out scene breaks and special margins.

I find the Calibre eReader gives a preview similar to ePub readers using an underlying Adobe RMSDK. I find Kobo kepub is less accurate at layout than kobo epub (current firmware on Original H2O and Kobo Libra).

I never installed KOreader on the Kobos because the stock reader works. KOReader is good for reading ebooks that have bad formatting, though I usually fix those on Calibre. I use KOreader on the Boyue Likebook Mars as the stock reader is great for PDFS but rubbish at implementing CSS and so I read good epubs or fixed epubs on the Libra and ones I can't be bothered fixing on the KOReader on the Mars as it can override nearly anything.

I use Lithium on Android for epub. A lot of supposedly popular Android epub apps are abysmal at respecting CSS and/or embedded fonts.

Curiously I find the lower resolution KK3 using KF8 slightly closer to Kobo Libra and Calibre Viewer epub rendering of a converted file than the PW3 (both using embedded Publisher fonts), especially on image size.

I've tested epubs on LCD Binatones with Adobe option, they need the DRM free epub in the ADE directory or else the rendering is terrible. Also Sony PRS-350, Nook Simple Touch, non-HD Cover Story, Kobo Touch, Original H2O and Libra.

I've tested converted epubs on these Kindles in our family: PW2, Basic with no front light, a mysterious old Basic that has 300 dpi (no front light), DXG, KK3, PW4 and once whatever Kindle has a D pad and no touch or keypad (but it's not a Kindle 1). Basically the KF7 (old Mobi) is poor on KK3 and worse on DXG (stock fonts) and on any Kindle with KF8 (either using dual mobi or AZW3) the results are close to epub.

I use both epub checks in Calibre and where the ebook is from ODT via DOCX export I check that the epub looks the same in the calibre viewer with a similar size window / font combo to H2O or Kindle PW3 appearance, with LO Writer page set to about Kobo Libra size rather than paperback or A4.

I've also tested two kinds of format on a 160 x 160 Palm PDA and epub Android from 4.x to 8.x on 4.3" to 10" screens. Aldiko Classic is next best to Lithium and installs on the ancient 4.3" Sony-Ericsson phone.

So do the Calibre book checking and test / read on Calibre viewer if you have nothing else.

The important things are being able to read epubs you get (may need fiixing in Calibre or KOReader overides) and being able to produce epub 2.x files that work reasonably on everything. Amazon KDP is best fed with epub 2 and they convert for the customer's selected Kindle. Google Playstore Books and Smashwords (and onwards to Apple, Kobo, Scribd, Barnes & Noble Nook) use the same epub2 file.

If the epub2 book looks OK in Calibre viewer and passes both the checks in the Editor, then it will usually be fine on everything, though degraded on KF7 only Kindles. I do check any epub using new styles or features I've not used before on the Original H2O, Libra, 5" Sony PRS350, Aldiko 4.3" screen, Lithium 6" and 10", and converted to Dual Mobi on the DXG, KK3 and PW3.

celiapgt · 04-19-2022, 01:21 AM

I appreciate your insight, davidfor!

My goal, obvoiously, is try to reach the maximun number of e-readers available, or at least the most used by people. That is why I assumed the ADE was the de facto standard. On the other hand, I dont' like the idea to narrow down the number of features available in CSS so most ereaders can render my books.

That's the thin ice I must transit on if I want to publish an ePUB.

celiapgt · 04-19-2022, 01:23 AM

Thank you, LinuxArie. I wasn't aware of the first link.

celiapgt · 04-19-2022, 01:31 AM

It is a good choice. No further installations if you already have calibre (I do)... But I do not know if it is a good choice to render as an Adobe RMSDK. That's my real question.

celiapgt · 04-19-2022, 01:38 AM

Thank you!

Excellent recomendations! I'm on Readium right now. You shed light a lot about the issue. I read your other comments, and your recommendation is very useful: to make good epub with CSS, not only using b, u, i.

I think maybe a note on the front of the epub to discourage the use of crappy ereaders, like MoonReader. (Too bad because the sync option with a cloud service is very useful).

celiapgt · 04-19-2022, 01:42 AM

Thank you for recommendation, skillachie!

Definetely I will take a look at your project. It is so good that new projects are on development. Please send me a DM with a review in Spanish so I can pass the info with my fellows (who also are interested in epubs). I'll be glad to help promoting it.

07-30-2021, 12:35 AM	#1
celiapgt EBook-obsessive gal Posts: 40 Karma: 10 Join Date: Mar 2011 Location: La ciudad de la eterna primavera Device: Kobo Clara HD	Linux ePub reader app that best fullfills the ePUB standard Hi, everyone! I'm trying to use an app for ePub reading in Linux that best fullfill the ePUB 2.x standard (I mean that I'm not interested in ePUB 3). Which one do you recommend? I always see so many differences between them with the same ePub file. I would love to know which is the most accurate to the fullfill the standard. I understand that no app does it completely. Maybe I am wrong. I'm looking at something able to render ePub files as close to the ADE does because I was told by Windows users that ADE is the standard app (?). Just to mention, I have tried KOReader, Foliate, ePUBReader, Calibre eReader, FBReader, CoolReader… Thanks for your suggestions. Last edited by celiapgt; 07-30-2021 at 12:35 AM. Reason: Legibility

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07-31-2021, 03:06 AM	#3
LinuxArie Connoisseur Posts: 71 Karma: 2703388 Join Date: Nov 2013 Location: 51,9°N 4,2°E Device: Kobo Touch & Clara HD. FBreader on Lenovo Yoga Tab 3 Pro, Nokia 3.1	Maybe these sites will help https://linuxhint.com/best_linux_ebook_readers/ https://itsfoss.com/best-ebook-readers-linux/

07-31-2021, 07:09 AM	#4
JSWolf Resident Curmudgeon Posts: 76,433 Karma: 136564696 Join Date: Nov 2006 Location: Roslindale, Massachusetts Device: Kobo Libra 2, Kobo Aura H2O, PRS-650, PRS-T1, nook STR, PW3	I highly recommend installing Calibre and using the Calibre eBook viewer.

08-07-2021, 06:00 AM	#8
Quoth the rook, bossing Never. Posts: 12,359 Karma: 92073397 Join Date: Jun 2017 Location: Ireland Device: All 4 Kinds: epub eink, Kindle, android eink, NxtPaper11	I think mangling in KOReader is sort of optional. You can set it that doesn't suck out scene breaks and special margins. I find the Calibre eReader gives a preview similar to ePub readers using an underlying Adobe RMSDK. I find Kobo kepub is less accurate at layout than kobo epub (current firmware on Original H2O and Kobo Libra). I never installed KOreader on the Kobos because the stock reader works. KOReader is good for reading ebooks that have bad formatting, though I usually fix those on Calibre. I use KOreader on the Boyue Likebook Mars as the stock reader is great for PDFS but rubbish at implementing CSS and so I read good epubs or fixed epubs on the Libra and ones I can't be bothered fixing on the KOReader on the Mars as it can override nearly anything. I use Lithium on Android for epub. A lot of supposedly popular Android epub apps are abysmal at respecting CSS and/or embedded fonts. Curiously I find the lower resolution KK3 using KF8 slightly closer to Kobo Libra and Calibre Viewer epub rendering of a converted file than the PW3 (both using embedded Publisher fonts), especially on image size. I've tested epubs on LCD Binatones with Adobe option, they need the DRM free epub in the ADE directory or else the rendering is terrible. Also Sony PRS-350, Nook Simple Touch, non-HD Cover Story, Kobo Touch, Original H2O and Libra. I've tested converted epubs on these Kindles in our family: PW2, Basic with no front light, a mysterious old Basic that has 300 dpi (no front light), DXG, KK3, PW4 and once whatever Kindle has a D pad and no touch or keypad (but it's not a Kindle 1). Basically the KF7 (old Mobi) is poor on KK3 and worse on DXG (stock fonts) and on any Kindle with KF8 (either using dual mobi or AZW3) the results are close to epub. I use both epub checks in Calibre and where the ebook is from ODT via DOCX export I check that the epub looks the same in the calibre viewer with a similar size window / font combo to H2O or Kindle PW3 appearance, with LO Writer page set to about Kobo Libra size rather than paperback or A4. I've also tested two kinds of format on a 160 x 160 Palm PDA and epub Android from 4.x to 8.x on 4.3" to 10" screens. Aldiko Classic is next best to Lithium and installs on the ancient 4.3" Sony-Ericsson phone. So do the Calibre book checking and test / read on Calibre viewer if you have nothing else. The important things are being able to read epubs you get (may need fiixing in Calibre or KOReader overides) and being able to produce epub 2.x files that work reasonably on everything. Amazon KDP is best fed with epub 2 and they convert for the customer's selected Kindle. Google Playstore Books and Smashwords (and onwards to Apple, Kobo, Scribd, Barnes & Noble Nook) use the same epub2 file. If the epub2 book looks OK in Calibre viewer and passes both the checks in the Editor, then it will usually be fine on everything, though degraded on KF7 only Kindles. I do check any epub using new styles or features I've not used before on the Original H2O, Libra, 5" Sony PRS350, Aldiko 4.3" screen, Lithium 6" and 10", and converted to Dual Mobi on the DXG, KK3 and PW3.

04-19-2022, 01:21 AM	#9
celiapgt EBook-obsessive gal Posts: 40 Karma: 10 Join Date: Mar 2011 Location: La ciudad de la eterna primavera Device: Kobo Clara HD	I appreciate your insight, davidfor! My goal, obvoiously, is try to reach the maximun number of e-readers available, or at least the most used by people. That is why I assumed the ADE was the de facto standard. On the other hand, I dont' like the idea to narrow down the number of features available in CSS so most ereaders can render my books. That's the thin ice I must transit on if I want to publish an ePUB.

04-19-2022, 01:23 AM	#10
celiapgt EBook-obsessive gal Posts: 40 Karma: 10 Join Date: Mar 2011 Location: La ciudad de la eterna primavera Device: Kobo Clara HD	Thank you, LinuxArie. I wasn't aware of the first link.

04-19-2022, 01:31 AM	#11
celiapgt EBook-obsessive gal Posts: 40 Karma: 10 Join Date: Mar 2011 Location: La ciudad de la eterna primavera Device: Kobo Clara HD	It is a good choice. No further installations if you already have calibre (I do)... But I do not know if it is a good choice to render as an Adobe RMSDK. That's my real question.

04-19-2022, 01:38 AM	#12
celiapgt EBook-obsessive gal Posts: 40 Karma: 10 Join Date: Mar 2011 Location: La ciudad de la eterna primavera Device: Kobo Clara HD	Thank you! Excellent recomendations! I'm on Readium right now. You shed light a lot about the issue. I read your other comments, and your recommendation is very useful: to make good epub with CSS, not only using b, u, i. I think maybe a note on the front of the epub to discourage the use of crappy ereaders, like MoonReader. (Too bad because the sync option with a cloud service is very useful).

04-19-2022, 01:42 AM	#13
celiapgt EBook-obsessive gal Posts: 40 Karma: 10 Join Date: Mar 2011 Location: La ciudad de la eterna primavera Device: Kobo Clara HD	Thank you for recommendation, skillachie! Definetely I will take a look at your project. It is so good that new projects are on development. Please send me a DM with a review in Spanish so I can pass the info with my fellows (who also are interested in epubs). I'll be glad to help promoting it.