Muhimbi’s PDF Editor for SharePoint lets you add comments to a PDF directly in SharePoint Online or On-premise. Start by dropping your comment to a specific location in your document and then customize its colors to make it stand out. Comments can also include a user's name to help you identify who left specific feedback on a document after multiple users have added comments.
Step 1: Open a PDF file
Select a PDF from the SharePoint library and right-click on the three dots menu. Click on Edit with PSPDFKit Editor.
Step 2: Add comments to PDF
Open the PDF annotations tool by clicking on the Note icon.
Select the exact area in the PDF document where you want to add comments and click on it to open the note field. Type the comment there and close the dialog. The PDF annotation will be saved, and you can drag it to another place within the document by holding the left mouse button.
Step 3: Edit comments in PDF
In the top left corner of the screen, you can see a wide range of options to change the look of your annotations in PDF. The default color of the note field is yellow, but there are five other colors to choose from. Also, you can change the look of the icon of the closed annotation depending on the type of comment added to a PDF document.
To delete annotations in PDF, click on the recycle bin icon in the top right corner. Finally, click on the Save button to save the changes to your PDF document.