How to Annotate a PDF: Highlight, Comment and Draw
Mark up any PDF with highlights, sticky notes, freehand ink and shapes — perfect for review, study and feedback — across all your devices with Falcon PDF.
Annotation is how you have a conversation with a document. Whether you're studying, reviewing a contract, or giving feedback to a teammate, marking up a PDF lets you capture thoughts without changing the underlying content. Falcon PDF keeps every highlight, note and drawing on a separate layer, so the original stays intact and your markup stays editable.
Annotation vs. editing
Annotations sit on top of the page. That's the key difference from editing a PDF, which changes the actual content. Annotations are non-destructive, easy to remove, and can be shown or hidden — ideal for collaborative review.
Highlight, underline and strike through
- Open your PDF and switch to the Annotate toolbar.
- Pick Highlight, Underline, or Strikethrough.
- Drag across the text you want to mark.
- Tap the mark to change its color or delete it.
Assign a meaning to each color — yellow for key points, green for approved, red for issues. It turns a long document into a scannable map of your thinking.
Add comments and sticky notes
Comments attach a written note to a specific spot on the page:
- Tap Comment and choose an anchor point.
- Type your note in the popup.
- A small marker shows there's a comment; tap it to read or edit.
Reply and resolve
When you share an annotated PDF, collaborators can reply within a comment thread and mark it resolved once it's handled — keeping the review organized in one place.
Draw freehand and add shapes
Sometimes a picture is faster than words:
| Tool | Best for |
|---|---|
| Ink / pen | Freehand circling, ticks, signatures on a diagram |
| Rectangle / ellipse | Boxing an area or drawing attention to a region |
| Arrow / line | Pointing at a specific element |
With an Apple Pencil or stylus, ink annotation feels just like writing on paper. Adjust stroke width and opacity from the toolbar.
If you want typed text rather than a note attached to a marker, use Add Text instead.
Organize and export annotations
- Open the Annotations panel to see every mark in a list.
- Jump to any annotation by tapping it, or filter by type or author.
- Export a summary of all comments, or flatten the markup into the page so it displays everywhere.
- Sharing a marked-up file? Compress it first with the compress toolif it's large.
Once you flatten annotations they become part of the page and can no longer be edited or removed. Keep an unflattened copy if you might revise your markup later.
FAQ
Are annotations compatible with other PDF apps? Yes — Falcon PDF uses standard PDF annotations, so highlights and comments open correctly in other readers.
Can I annotate on any device? Yes, on iOS, Android, Mac, Windows and Linux. Download Falcon PDF and your markup syncs with the file.
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