Some epub apps will install basic epub support for QuickLook. So you may already be able to view epub files with Quicklook. Either way, here are a couple of QuickLook plugins that will provide quick access to the ebook’s cover image (assuming it has one) and to any metadata stored in the epub in both QuickLook and Spotlight.
For example, here’s the QuickLook view of one book on my computer, as generated by this plugin:
Follow these steps to achieve this great QuickLook functionality on your Mac:
1) Download the ePub Plugins v1.5.dmg file from here (NB. the version number in the file name might be newer).
2) Open the DMG file and follow the instructions in there. Or the instructions below…
You’ll need to drag the epub.qlgenerator file into /Library/QuickLook (for all users) or ~/Library/QuickLook (for the current user only). I suggest you make life easy and just put it into the one for all users, as there is already a shortcut in the DMG file to drag it to.
Then drag the epub.mdimporter file into /Library/Spotlight (for all users) or ~/Library/Spotlight (for the current user only). Again, if you can just go with the one for all users, as there is a shortcut in the DMG for that.
Kicking Spotlight into life
On my computer, Spotlight automatically pulled in data from my epub files. However, the developer of the plugin indication you may need to first make it index your EPUB files. One way he suggests for doing this is to run Terminal.app and enter this command:
(if you put the plugin into your All Users / System Library)
mdimport -r /Library/Spotlight/epub.mdimporter
mdimport -r ~/Library/Spotlight/epub.mdimporter
Spotlight will create a preview similar to this…
Kicking QuickLook into life
After a few seconds QuickLook should load new plugin. If it is not loading as quickly as you would like, you can type the following command into Terminal.app to give it a move along.
Conflict with other QuickLook generators
epub.qlgenerator can conflict with other QuickLook generators (notably BetterZipQL under OS X 10.6 and earlier). To fix this, rename epub.qlgenerator to come before the conflicting plugin alphabetically (for example AA_epub.qlgenerator should work).