Annotation Types

The most common types of PDF annotations are:

• Text markup annotations — These annotations are used to highlight or underline specific text within a document. They include highlight, underline, and strikethrough annotations.

• Text box annotations — Text box annotations allow users to add additional text or comments to specific areas of a document. They appear as rectangular boxes that can be placed anywhere on the page.

• Sticky notes — Sticky notes are small, customizable pop-up windows that can be attached to specific points on a page. They’re commonly used for leaving comments, providing feedback, or adding supplementary information.

• Link annotations — Link annotations enable the creation of hyperlinks within a PDF document. They can be used to link to external websites, other pages within the same document, or specific locations within the document.

• Stamp annotations — Stamp annotations are used to apply predefined graphical images — such as signatures, company logos, and official seals — onto a PDF page.

• Drawing annotations — These annotations allow users to draw shapes, lines, arrows, or freehand sketches directly on a PDF document. They can be used for highlighting areas of interest, adding visual explanations, or creating diagrams.

• File attachments — File attachment annotations allow users to attach additional files — such as images, documents, and multimedia files — to a PDF document. These attachments can be accessed and opened by users viewing the PDF.