Annotate PDF
Highlight, underline, strike-through, and add sticky notes anywhere in your PDF.
shieldFiles stay on your device — processing runs in your browser.
- check_circleHighlight, underline, and strike-through real text selections
- check_circleFree-hand pen and shape annotations on any page
- check_circleAll markups export back into the PDF as standard annotations
Annotate and mark up PDFs without uploading them
Add highlights, underlines, strike-throughs, freehand drawing, shapes, and sticky notes to any PDF. LumosPDF saves them as standard PDF annotations, so they open correctly in Acrobat, Apple Preview, and other readers. All markup happens locally in your browser — your document is never sent to a server.
How to annotate a PDF
- 1Upload your PDF using the drop area above.
- 2Select text to highlight, underline, or strike it through, or pick the pen and shape tools to draw freely.
- 3Add comments and notes wherever you need them across any page.
- 4Export the annotated PDF to download it with all markup baked in.
Frequently asked questions
Will my annotations open in other PDF readers?
Yes. LumosPDF writes standard PDF annotation objects, so highlights, notes, and drawings display correctly in Acrobat, Apple Preview, and most other viewers.
Can I highlight real text or only draw boxes?
Both. You can select actual text to highlight, underline, or strike through, and you can also draw free-form highlights and shapes anywhere on the page.
Are my documents private?
Completely. Annotation runs entirely in your browser; the PDF is never uploaded, so no one else can see it.
Does it cost anything?
No. Annotating PDFs on LumosPDF is free with no account required.
Can I remove an annotation later?
Yes. While editing you can select any annotation and delete or adjust it before exporting.