Every markup tool you need
Highlight and strike-through snap to the lines of text you drag across, so marks look neat even on dense pages. Draw freehand with a mouse, trackpad, stylus or finger. Add text notes, boxes, circles and arrows to point things out. Pick a colour and a size before you start, or select a mark and change it afterwards.
Editable comments or part of the page
Editable comments are saved as standard PDF annotations, the same kind Adobe Acrobat and Apple Preview create, so anyone you send the file to can move, change or remove them. Choose part of the page when the marks should stay exactly as they are, for example on a signed form or a marked exam.
Privacy
Your PDF is opened and saved in your browser. Nothing is uploaded, and the file is gone from this page when you close it.