Reviewing without printing
Teachers marking assignments, managers reviewing drafts, lawyers checking contracts and students studying notes all need to mark up documents. Printing, writing with a pen and scanning is slow. Annotations let you highlight, comment and draw directly on the PDF and send it straight back.
How it works
Choose Highlight, Comment or Freehand drawing, pick a colour, and type the comment text when needed. Then drag on the page preview to mark an area, or draw freely. Each mark uses the settings active when you made it. You can add up to 200 marks, remove a mark by clicking it, and also add rectangle marks precisely with the keyboard controls.
Real PDF annotations
The marks are saved as standard PDF annotations, not burned into the page. That means readers see them in Adobe Reader, Edge, Chrome and other viewers, and they can be hidden, edited or deleted later. The original page content underneath stays unchanged.
Common problems and how to fix them
“Marked pages require 0° rotation”: rotate the PDF upright with Rotate PDF first, then annotate. Comments do not show in a phone app: some simple viewers ignore annotations — try Adobe Reader or a browser. You want marks that cannot be removed: print to PDF from your viewer, or use Watermark PDF for permanent text.
Good habits
Use one colour per meaning (for example yellow for important, red for errors), keep comments short and specific, and keep the unmarked original.