I noticed today that the Firefox browser for Android has a nifty built in feature that lets you save a web page as PDF. It will save the entire web page and not just what is visible on the screen. It completely scrolls down the page and saves it as PDF.

Firefox might not have come installed on your phone, but you can get it from the Play store. 

To save a web page as a PDF file in Firefox for Android:

  1. Visit a web page
  2. Tap the three dot menu
  3. Go to "Page -> Save as PDF"

Following those steps will automatically save the web page you're viewing as a PDF. 

It will save the PDF to your phone or device and you will see a notification on your screen when the download is completed.

Note that you might see formatting inconsistencies between the way the web page is displayed in the web browser and how it's displayed in the PDF. 

Also, this is not a screenshot of the page that is simply pasted into a PDF file, it is the actual web page that is rendered as a PDF using a special rendering engine for that. This results in a PDF where text and other objects can be selected.