Mendeley Desktop and mobile apps allow you to read and annotate your PDFs* within the Mendeley platform.
1. Double click on a source from your library to open it in the Mendeley PDF viewer
2. Use the features in the annotation tool bar to highlight text, and add your own in-text notes
3. After your annotations are complete, click the "Sync" button to ensure your highlights and notes appear across all Mendeley platforms
*Annotations made to the document while in a Mendeley platform are saved to your Mendeley account, and not saved directly to the PDF. This means your annotation will only be visible when reading the file from Mendeley Desktop or the mobile app.