Want to use your iPhone as an ebook reader? With iBooks app it's easy to store and read your ebooks that purchased from the iBooks Store or elsewhere (make sure they're in the .epub or .ibooks format). However, there are still many great books which are PDF files. How to upload PDFs to iPhone? This can be done by using the iBooks app or iOS Manager, which is pretty easy.
Method 1: How to Transfer PDFs to iPhone from iBooks App
You can directly add PDF to iBooks from iBooks on iPhone. Just make sure you have iBooks app preinstalled on your iPhone 7 Plus, 7, SE, 6s Plus, 6s, 6 Plus, 6, 5S, etc. Compared with transferring PDF files to iPhone with iCareFone, this method below seems to be a little complicated. If you want easier steps, turn to Method 2.
Open iTunes on your computer. In iTunes library, click Books. If you can't find this listed in the Library (the first option in the menu bar on the left), you should edit your Preferences in the main iTunes menu to make sure Books are selected.
Make sure you can see your PDF via a file browser (such as Finder on Mac or Explorer on Windows) or as an icon on the desktop.
Drag and drop the PDF file into your iTunes Book library. Then the PDF files will appear in both places. Connect your iPhone into your computer and then select it in the Devices menu on iTunes. Then click on the Books tab in the resulting phone screen within iTunes.
Check Sync Books. You can choose either to sync all books (meaning all seen in your iTunes Book Library will be uploaded to your iPhone) or to sync selected books (meaning only the books that you check off will be uploaded to your iPhone).
Click the Apply. Your iPhone will automatically sync with iTunes.
Once you've transferred PDF files to your iPhone, you can print PDFs and notes you've entered from iBooks.
Method 2: How to Add PDF to iPhone with iCareFone
An easier to sync PDF to iPhone is using iCareFone, a third party software tool, which requires only a few clicks of your mouse to successfully sync PDF to iPhone. This tool not only supports iPhone, but also supports all the iOS 10/9/8/7 devices including iPhone 7/7 Plus, iPhone 6s/6s Plus, iPhone SE, iPhone 5s/5c, iPad Pro and iPhone Air.