In the case you want to save a webpage as PDF to your iPhone/iPad, follow the similar steps as above:

Tap the share icon>“Copy to iBooks”, you will find the PDF file is saved to your iPhone/iPad in iBooks.

Open the email with PDF attachment, then tap the PDF file.

If the PDF is attached in your email, iBooks can also help save the PDF attachment to your iPhone/iPad. Save Email-Attached PDF to iPhone/iPad (iPhone 8 Included)

Tap the PDF file and click “Open in iBooks”, and the PDF file will be saved to your iPhone/iPad.

Open the webpage with Safari and find the PDF you want to save to iPhone/iPad.

Save Online PDF to iPhone/iPad (iPhone 8 Included) With this program, you will be able to read PDF on iPhone/iPad from web or email box conveniently. It supports ePub, iBook Author books, PDFs, MP3 audiobooks, AAC audiobooks. You can view, download, even organize e-books within the program. IBooks is a pre-installed e-book application in iOS or MacOS.

Save PDF to iPhone/iPad iCloud (iPhone 8 Included).

Transfer PDF from Mac to iPhone/iPad (iPhone 8 Included).

Save Email-Attached PDF to iPhone/iPad (iPhone 8 Included).

Save Online PDF to iPhone/iPad (iPhone 8 Included).

How to download a pdf on an iphone