Zotero PDF reader
Zotero has a built-in PDF reader that you can use to read and annotate the full-text items in your library. Annotations are stored in the Zotero library, rather than within the PDF, and so annotations to items in group libraries can be seen by all the group members.
Using the Zotero PDF reader
Open the reader by double-clicking on a PDF attachment in Zotero. A toolbar at the top of the page offers several ways you can mark up important information in the PDF:
Highlight text- Underline text
- Add note
- Add text
- Select area
- Draw
You can choose from several colors if you would like to color-code your annotations.
Using other annotation tools
If you already have a preferred application for reading and annotating PDFs, you can tell Zotero to use that application instead of the built-in reader.
In the Zotero settings, go to the "General" pane and look for the "Reader" settings.
See more on the Zotero PDF Reader and Note Editor.