What it does
PDF Annotator lets you add highlights, notes, shapes and freehand drawing onto PDF pages and save the marked-up file.
- Highlights, notes, ink
How do I annotate a PDF?
Annotate a PDF by uploading it and adding highlights, text notes, shapes, freehand drawing and comments directly on the pages. Position and colour each markup, then download the annotated PDF. Everything is drawn in your browser, so the document stays private.
- Highlight, underline and strike-through text
- Add text notes, shapes and freehand ink
- Choose colours and thickness
- 100% client-side
What is
PDF Annotator
A tool for marking up PDF pages with highlights, notes, shapes, freehand drawing and comments, saved into the document.
PDF Tools
Related terms
markupsign PDF
Frequently Asked Questions
Yes.
Add highlights, underlines and strike-throughs, plus sticky notes and freehand drawing anywhere on the page.
Yes.
Use the pen tool to draw or sign, choosing colour and stroke width.
No.
Annotations are rendered locally and saved with pdf-lib.
Detailed Explanation
How it works
Markups are drawn on an overlay and written into the page content or annotation layer with pdf-lib on export.
- Overlay to pdf-lib
Use cases
Review documents, mark corrections, sign informally, or add comments before sharing feedback.
- Review and feedback
Limitations
This is a markup tool, not a full text editor; it adds annotations on top rather than reflowing the original text.
- Overlay, not text edit
Privacy
All annotation happens in the browser; the file is never uploaded.
- 100% local