Firefox lets you take full-page screenshots that you can share or save as PDFs on your device.
To take a full-page screenshot:
- Go to the website you want to save as PDF.
- Hold down the volume up and side button at the same time to take a screenshot (for iPhones with Touch ID, press the side button and the Home button at the same time).
- Tap the screenshot thumbnail that appears on the lower right side.
- In the screen that opens next, tap the Full Page option at the top right.
- Tap Done to save the entire web page.
- Tap Save as PDF.