To convert Web pages to PDF on an iPhone, install Google Chrome on the iPhone. Sign up for a free Google account, which comes with the Google Drive and Google Cloud Print features. Log in to this account in the Google Chrome app. Open the Google Chrome app and go to a Web page. Once there, tap the menu, tap Print, and tap Save to Google Drive. This saves the Web page as a PDF file in Google Drive.
Alternatively, use a PDF File Conversion service by creating a bookmark in a browser. Open a browser app such as Safari on an iPhone and go to any Web page. Tap the Share icon and tap Add Bookmark. Once bookmarked, change the name of the bookmark to "Save as PDF." Tap Save to save the edited bookmark.
A third way to convert a Web page to PDF on an iPhone is using an iOS app, such as To PDF, that supports this feature. Download and install the free To PDF app from the iOS App Store on an iPhone. This app adds a "Convert to PDF" option to the Share menu of a browser app such as Safari.