Highlight, underline, and strike out text in a PDF using Preview on Mac
You can use the highlight, underline, and strikethrough text tools to draw attention to text in a PDF. These marks are often used in conjunction with speech bubbles and notes.
Highlight, underline, or strike though text
Go to the Preview app
on your Mac.Open the PDF you want to change.
Do any of the following:
Quickly highlight, underline, or strike through text: Select text, click
next to 
, then choose a highlight color, underline, or strikethrough.Use highlight mode: Click
(so it turns gray), click next to , then choose a highlight color, underline, or strikethrough. Now, whenever you select some text, the highlighting style you chose is automatically applied to the text.To turn off highlighting, click
again.Remove a highlight, an underline, or a strikethrough: Control-click the text, then choose Remove [item] from the shortcut menu.
View all the highlights in a PDF
Go to the Preview app
on your Mac.Open the PDF you want to change.
Choose View > Highlights and Notes (so Highlights and Notes has a checkmark next to it). Each section of highlighted text appears in the sidebar.