EPUB is a free and open e-book standard by the International Digital Publishing Forum (IDPF), and it is also the most popular eBook format used by almost all the important online eBook retailers except Amazon.
It is precisely because EPUB is free and open, so any people can make a .epub file according to the guideline. But that leads to a problem that not everyone is able to make a perfect .epub file. Even some EPUB books downloaded from online stores might not in standard structure, yes maybe we can read it on their application such as Sony Reader, Kobo Reader, etc., but in fact, it has some issues in file structure. For some worse files, they even can't be opened.
In fact, many damaged .epub file are pretty easy to fix. Just 3 simple steps, we can fix EPUB file and read it perfectly. And I will take an .epub file which is provided by one of our clients as example, who wrote the book and turned it into EPUB himself, and I put this book on the free book introduction page.
A damaged EPUB file can't be opened by reader software
First I load this book into Sony Reader for PC software, and it tells me "The file may be corrupted".
Then I tried to open it with Adobe Digital Editions 2.0, and it also tells me "Errors were encountered in this item".
In the past, I will give up reading the book. But now, we can bring this file back to life with this guide.
Fix the EPUB with 3 steps
1Install a Zip software
There are 2 mainstream free Zip softwares, WinZip and 7-Zip. Unfortunately, they all fail to do the epub-fix job in my tests. So in this post, I will take HaoZip as example, which is also a free Zip software developed by a Chinese company. Click the link to download it from their official site for free.
2UnZip the EPUB file
Use Zip software to unzip the EPUB file. If you can't directly unzip the EPUB file, try to rename the extension name from .epub to .zip, then unzip it.
3Re-Zip the file and change extension name to EPUB
We are not missing any step, yes we just need to zip the folder again. Right click on the unzipped folder, and choose "Add to Archive".
Attention! This is the key-step! Don't directly zip the folder to a .zip file. You should rename the extension name to .epub in zip settings. Then click OK, job done!
Now try to read this fixed EPUB file with Sony Reader or Adobe Digital Editions. Look at the screenshot below, it can be read by ADE perfectly!
FYI: Epubor EPUB to PDF Converter can handle broken EPUB file
The latest version of EPUB to PDF Converter has integrated the EPUB fixing feature. Before the conversion starting, the software will repair the corrupt EPUB file automatically (depends on the extent of damage).
So if you have some damaged EPUB files and accept converting them to PDF, please try to use EPUB to PDF Converter to bring them back to life. Don't worry about paying for the product but it can't convert your damaged EPUB files, 30-day free trial is available to anyone.
Jonny Greenwood joined Epubor since 2011, loves everything about eBooks and eReaders. He seeks the methods to read eBooks more freely and wants to share all he has got with you.
I'll share this experience to anyone encountered this problem
Thanks
Could you send me the file?
Thank you.
I think it is easier to use WinRaR to fix the file without changing file extension
then I've got a rebuilt version of the same file.
WinRaR is fine with me.
I just fixed an epub.
Thank you so much.
I was able to unzip/zip, changing the extension changed from .zip to .epub ..... but alas it still did not open for editing in either Sigil or Calibre.
It's horrifying to me that this can just happen out of the blue when all you're doing is editing your HTML/CSS in Sigil. Not only that, but my last 2 backups are suddenly rendered useless too apparently. WTF??? What abysmal software. All I've been doing all along is gradually editing the CSS/HTML (which I used to do for a living BTW). If I'd known how randomly volatile it was, I wouldn't have used this software.
Hopefully there's a silver lining though. I had a look in the unzipped folder I got after step 1 and stumbled on the HTML file with all my latest changes in. In the absence of a working epub file, this is absolute gold dust to me. Otherwise I lose weeks of work, all of which was just incremental changes to the HTML/CSS. Nothing clever.
So now I have the latest HTML file, I'm hoping to:
(1) Use Sigil to recreate a fresh epub file from my old original filtered HTML document(saved from my original Word file weeks ago). This is just a dummy/surrogate working file to replace the corrupted one.
(2) Open this new file up for editing and paste the contents of my most recent HTML file(from unzipped folder) over the HTML in the dummy file.
(3) Then take it from there. Saving regularly of course!
I think part of my backup routine in Sigil from now on will be to unzip the file and save the HTML as well as the epub, just in case!!! It's a ridiculous way to work though.
Anyway thanks for the heads up about unzipping - I had no idea that was even an option when I was doing back-flips tearing my hair out in the early hours last night. It's so creepy this can just happen out of nowhere like that. Something's fundamentally wrong with the software for this to be able to happen. I don't care what anyone says. I didn't do anything out of the ordinary here - just edited HTML and CSS. I was nearly finished! Evil!
hi;
I have 3 .epub files but can not open them.
when i want convert them your software show this message:"Encounterred Error,the conversion failed."
can you help me?
thank you.
(if you want; i can send file.only please send me your email)
Thank you for using Epubor software. For converting these epub files, you need to ensure they can be open at your computer.
Where did you purchase these books?
It works
and if the link doesn't works then use https://softfamous.com/haozip/
:)
Chinese Website blocked by MalwareBytes due to Trojan.
Just purchased epubor. Excellent and easy.
Tip: show the title cover page in the trial version. Removes doubt at potential customers.
Problem: 4th book (recently bought) I tried to convert is readable in ADE, but fails to decrypt: Adept DRM message.
Please help!