How to Fix EPUB Files

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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".

sony can't open the damaged epub

Then I tried to open it with Adobe Digital Editions 2.0, and it also tells me "Errors were encountered in this item".

ade fail to open damaged epub file

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.

download haozip

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.

unzip epub file

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".

zip a folder to epub

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!

rename the extension name to epub

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!

how to fix a epub file

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.




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.

06/2/2014 14:08:39
03/18/2017 07:11:33
ARE YOU ALL PAID e_e to make a good review about this program?
07/3/2014 02:05:11
Thank you very much, it's so amazing.
I'll share this experience to anyone encountered this problem
07/19/2014 13:40:25
This worked like a charm using WinRar.  Fantastic tip.  Thanks a lot.
07/19/2014 14:19:01
This worked like a charm using WinRar.  Fantastic tip.  Thanks a lot.
07/25/2014 06:21:11
Great - Thank you!
10/3/2014 13:21:43
Re-zipping it did not work for me, and the Epub converter program only converts 10 pages in the trial version.
10/4/2014 06:25:45
Could you please send the ebook file to me for ckecking?
12/30/2014 04:47:49
Thank you!Very helpfull
01/17/2015 15:27:30
Re-zipping did not help at all; it only created a folder that I still cannot access. Please help?
01/19/2015 03:00:54

Could you send me the file?

Thank you.

01/19/2015 00:25:08
Thank you! I rename the file extension to .rar and use winrar to repair it and use the new file and change the extension back to .epub and it work.
03/12/2015 03:20:12

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.

03/17/2015 09:02:21
Didn't work for me, still getting error after it's zipped back up :(
03/18/2015 00:40:09
Looks like your EPUB is heavily damaged, as the method only fixes slightly damaged EPUB file.
10/6/2015 05:05:50
If this solution did not work, look for an expert to fix epub errors. fiverr.com/pinkszzz/fix-epub-errors-of-all-types-with-full-guarantee
11/23/2015 16:26:08
Hi, I tried this method but it didn't work. It reads on e-readers but Google Play Books can't process it. Do you know why this would be the case?
11/27/2015 18:28:48
Thanks, it was very helpful!!!!!!!!!!!!
12/25/2015 14:30:09
yeah, it works!! :)
02/25/2016 07:11:53
I just fixed an epub.
Thank you so much.
05/8/2016 08:14:28
Omg...thank you so much for this guide! I was giving up but then i found your article and this was super helpful! Thank you again:))))
03/17/2017 05:08:27
Having problems with pages being out of order and looping the reader back to pages already read. Downloading book and transferring to Kindle worked flawlessly.
05/10/2017 18:17:41
And what if the damaged epub file is a library book downloaded on to an e reader (Tolino) and therefore the epub file is hidden? Is there help for me too
07/18/2017 21:30:11

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!

12/1/2018 00:09:21
thank you so much. it works like a magic :D .. cheers for yah !
05/3/2019 03:17:26

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)

05/5/2019 11:18:47

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?

08/17/2019 07:41:29
Thank you very much!
11/23/2019 01:40:57
Thank you.
It works
and if the link doesn't works then use https://softfamous.com/haozip/
07/16/2022 00:27:17
Trojan on that Chinese zip program link.
07/21/2022 17:08:33
Dailed without valid reason so am uninstalling
10/31/2022 12:53:44

Chinese Website blocked by MalwareBytes due to Trojan.
12/11/2022 22:23:46

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!

12/22/2022 16:07:49
Thank you for using our software. Please let us know where did you purchase these adobe files.
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