Annotating PDFs
Need to mark up a PDF? Add highlights, comments, drawings, arrows, stamps - all in your browser. Good for reviewing documents, collaboration, taking notes on papers. No specialized software needed.
Upload
Upload your PDF. Drag or click. Displays almost immediately.
Tools
Left sidebar has everything:
- Select: Click and drag existing annotations to move
- Text: Add text anywhere
- Highlight: Mark important text with color
- Drawing: Freehand drawing
- Line: Straight lines
- Arrow: Point to stuff
- Rectangle: Box around sections
- Circle: Circular highlights
- Comment: Sticky-note style comments
- Stamp: Pre-made stamps like "APPROVED"
- Eraser: Remove annotations
Creating Annotations
Select tool, then:
- Text: Click where you want it, type
- Highlights: Click and drag over text
- Shapes: Click and drag to define size
- Drawings: Click and drag to draw
- Stamps: Click where you want it
Customizing
Each annotation can be customized:
- Colors: 14 options including yellow for highlights, red for corrections
- Font size: 8px to 72px
- Stroke width: Line thickness
- Opacity: Make more/less transparent
- Categories: Important, Question, Todo, Note, Review, Error, Suggestion
Managing
Right sidebar lists all annotations:
- Search for specific ones
- Filter by category
- Toggle visibility
- Lock/unlock to prevent editing
- Delete what you don't need
Click any annotation in list to jump to its page.
Navigation
Page controls at top:
- Go to specific pages
- Move forward/backward
- Zoom in/out
- Fit to screen
Saving
When done:
- Save as Image: Current page as PNG with annotations
- Export Annotations: Save just annotations as JSON
- Import Annotations: Load previously saved annotations
Collaboration
Good for team review:
- Different people use different colors/tools
- Add detailed comments for others
- Use arrows and shapes to point to issues
- Stamps for quick status marking
Annotations layer over PDF without changing original. Can always remove later. Good for students, professionals reviewing docs, editors, anyone adding temporary notes or marks. Works in browser, no installation.