Zipping and Unzipping an ePUB

An ePUB file is basically all of the content you’d find on a website (HTML, CSS, XML and images) zipped up into an archive. When you are creating a new ePUB file, or revising one that is owned by yourself or your employer, you might find that you need to unzip the archive in order to access or make changes to the content within.

There are a few different ways you can open up an ePUB file. On a PC, you can simply change the file extension from .epub to .zip. On a Mac, you can use Terminal, but the easiest way to unzip and re-zip an ePUB file on either system is using a program like eCanCrusher.

Unzip Your ePUB on a Mac:

  1. Save the ePUB file somewhere you can easily find it, like your Desktop
  2. Download eCanCrusher and save it to your Desktop, too
  3. Drag the ePUB file onto the eCanCrusher icon and it will automatically unzip, creating a new folder in the same location as the ePUB



On a PC:

  1. Save the ePUB file somewhere you can easily find it, like your Desktop
  2. Download eCanCrusher and save it to your desktop
  3. Open the eCanCrusher folder, and create a shortcut to save the program on your Desktop:


4. Drag and drop the ePUB onto the eCanCrusher icon on your Desktop, just like in the Mac screenshots above

Note: You might run into the following warning on a PC:


If you do, it should be fine to click ‘More Info’ and then ‘Run Anyway’


Always check with your IT department before downloading new programs though, to make sure that you are in accordance with company policies.

Re-Zip Your ePUB File:

On a Mac or a PC:

  1. Save any changes that you have made to the files within the ePUB folder
  2. Drag the un-zipped ePUB folder back onto the eCanCrusher icon on your desktop, et voila! A freshly zipped ePUB will appear on the desktop.


Up next: What’s in an ePUB? The Root Directory