During the development of your EPUBs, use the book proofing tool in Apple Books for OS X Yosemite or later to rapidly proof books and sync your proofed books to your iOS devices. Once you have your proof set up on your Mac and iOS device, changes you make to your EPUB will update automatically in Apple Books on your Mac and any iOS device you have synced. If your EPUB includes interactive content, the book proofer in Apple Books lets you see and interact with your book the way your readers will; you can make sure everything looks and works to your satisfaction before you distribute your book or submit it for sale on Apple Books.
To prepare your EPUB for proofing:
Before you can create an EPUB proof, make sure your EPUB is in the right format (a folder, not a flat file). To check this, right-click your EPUB and see if Show Package Contents appears in the menu. If so, you're ready to create your EPUB proof. If not, follow these steps:
Create a new folder on your Desktop or in Finder.
Launch Terminal. You can search for it in Spotlight, or go to Applications > Utilities in Finder.
In the Terminal window, type cd followed by a space
Drag the folder you created into the Terminal window and press Return.
Type unzip followed by a space.
Drag your EPUB file into the Terminal window and press Return.
Right-click the folder you created and choose Get Info
Under Name & Extensions, add .epub to the end of the folder name.
To enable book proofing:
Go to the Apple Books menu in OS X Yosemite or later and select Preferences.
Go to Advanced.
Check the box for “Enable Advanced menu in menu bar.”
To add a book proof:
Go to the Advanced menu and choose “Add EPUB to Library as Proof…”
Select your EPUB file in the chooser that appears.
Your EPUB will appear in your Apple Books Library with a Proof badge.
To sync your proof from Apple Books in OS X Yosemite or later to iBooks 1.5 or later on your iOS device using iOS 5 or later:
Connect your iOS device to your Mac.
Open Apple Books on your iOS device.
Open your EPUB proof in Apple Books on your Mac.
Click the “Devices” button in the toolbar.
Check the box next to each device you would like to sync.