How to Underline Text in a PDF on iPhone

Download Highlights for free. Not on an iPhone? Checkout the Mac and iPad guides.

1. Open the PDF document in Highlights

Tap the PDF you want to open in the Highlights document browser:

iPhone displaying Highlights document browser

The PDF opens full screen:

iPhone displaying a PDF document open in Highlights

2. Select the text you want to underline

This will bring up the selection popover:

Text selection popover

3. Tap the underline button in the selection popover

Underline icon

Your annotation is added to the PDF and the text you underlined appear in your notes which you can easily share.

Similarly, you can also highlight and strikethrough text in PDFs.