What's the difference between fixed layout ePub3 vs PDF?

[apastuszak]

Obviously, there is a difference in the file format. But is there some reason you would pick PDF over fixed layout ePub3 or vice versa?

[Turtle91]

There are more devices/apps that support pdf. It’s easier to create a pdf…. “Print to pdf”, etc. Fixed Layout is a bit more difficult to create……
But reading a book in pdf format is not an enjoyable experience. The zooming and panning required, especially on a smaller device, gets really irritating really fast!
On a fixed layout you can still use a lot of the epub functionality, like JavaScript, that you can’t whenever reading a picture.

[Quoth]

If it's fixed layout, then use PDF.
Anything else is an attempt to sell fixed layout / print replica as ebooks. Fixed layout or Print Replica or PDF are electronic format books, but not true ebooks. True ebooks reflow to any size screen, even if font size & line spacing changed to suit user.

I may buy a 14.25″ tablet shortly for fixed layout, Print Replica and PDF. The 10.9″ is only mostly big enough.
The Kindle DXG 9.7″ was a failure. So was the 10.3″ Kobo Elipsa and the reMarkable. The 8″ Kobo Sage is OK for small PDF instruction booklets/manuals. More pixels than DGG, reMarkable or Elipsa. The Kindle Scribe is too walled in.

[Tex2002ans]

Originally Posted by apastuszak

Obviously, there is a difference in the file format. But is there some reason you would pick PDF over fixed layout ePub3 or vice versa?

If you want some more info on "Fixed Layout EPUBs (FXL) vs. PDFs", see the discussion in:

• 2022: "Two-pages image (facing pages) / How to?"
  
  • Especially Booknook.biz's page on "Kid's Books".
    
  • Note: Hitch is the MobileRead user and owner who runs that conversion company. Anything she says should be held at the highest value.
    

For a little more Fixed Layout discussion we've had over the years, see:

• 2019: "ePub format looks right on Calibre/Play Books but not in other ebook reader"
• 2021: "Indesign-epub-kindle formatting problem: footnotes export with massive indent."
  
  • This discussed some of the internal code from InDesign's iBooks-only formatting + how to try to clean it up.
    
• 2023: "Help: missing embedded fonts after ePub3 transfer to Kindle"
  
  • I linked to 2 Reddit topics where I broke down and discussed even more FXL things in detail.
    

And here's a snippet I wrote in that 2019 topic:

Originally Posted by Tex2002ans

FXL has been discussed extensively on MobileRead in other topics, and Hitch [...] has written a few blog posts about the advantages/disadvantages:

http://www.booknook.biz/ebook-conver...ooks-as-ebooks
http://www.booknook.biz/our-ebook-pr...-format-ebooks

Long story short:

• Extremely expensive to produce
• Each device/store is going to need their own unique variants
  
  • File that works in iBooks doesn't work in Kobo/B&N/Amazon.
• Very poor reading experience
• Loses all the advantages of actual ebooks (reflowability + following user preferences).

Nothing has changed on that front. FXL EPUBs are still just as awful as they were back then.

(Like jhowell said, the panning/scanning required is so annoying!)

- - -

99%+ of ebooks can be completely reflowable and DO NOT need Fixed Layout at all.

One of the only "pros" of FXL EPUBs is... the largest ebook stores (Amazon, B&N, Kobo, etc.) don't let you sell PDFs directly to customers. So if you wanted to do something like sell a specialized textbook, cookbook, or children's book, the FXL EPUB may be one avenue you can use to get a non-physical version into readers' hands.

But that's about it... in almost all other cases, PDF > FXL EPUB.

(Normal, reflowable EPUB is better than all though! )

- - -

Side Note: If you want to find even more of the discussion, just type this into your favorite search engine:

• "Fixed Layout" EPUB PDF site:mobileread.com

and you'll find plenty of topics.

[Quoth]

I suspect there is a way, but not via KDP, to publish PDF on Amazon. The customer doesn't get a PDF, but it's a PDF inside. There are maybe azw* and KFX fixed layout (Print Replica) on Amazon that are really PDF.

Historically Amazon Print Replica (fixed layout) was only for the App (inc Fire), not eink Kindles, but the Scribe might work.

The bigger publishers do not use Amazon KDP.

EDIT / PS:

I did get a 14.25″ Nxtpaper 3.0 tablet since I wrote before (TCL NxtPaper 14) and first time in 30 years of portable gadgets I can now read ANY document on a portable device. The Kobo eink 7″ Libra or 8″ Sage is still better for reflowable novels, mostly due to size.
I once nearly bought a Sony DPT, and glad I didn't. The two 10.3″ eink were not good enough (reMarkable and Elipsa) and are now given away. The 9.7″ Kindle DXG was always pointless for PDF. Too low resolution (150 dpi), too small and too slow.

[JSWolf]

a .azw4 file is a PDF in a KF8 wrapper.