Load a PDF, choose Highlight or Pen, and mark up the page. The marks are baked into a new PDF — in your browser.
Drop a PDF here, or click to browse
.pdf · stays on your device
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How to Annotate a PDF
Three steps, all in your browser.
1
Add your PDF
Drag in a PDF or click to browse. The first page appears ready to mark up.
2
Highlight or draw
Choose Highlight or Pen, pick a colour, and drag on the page. Switch pages to annotate more; use Undo or Clear page as needed.
3
Save and download
Click Save Annotated PDF to download a copy with every mark baked in.
For a signature specifically, use Sign PDF. Add Image to PDF places a picture, Watermark PDF stamps text across pages, and Flatten PDF locks filled form fields once you are done.
Annotation settings
The pen colour and width, and the page the marks are applied to.
| Setting | Range | Default |
|---|---|---|
| Pen colour | Any hex colour | #ffd400 |
| Pen width | 1 – 16 px | 4 px |
| Page | Any page number in the document | 1 |
| Output | Marks are drawn onto the page, not stored as PDF annotations | — |
Frequently Asked Questions
How do I annotate a PDF?
Load your PDF, choose the Highlight or Pen tool and a colour, then drag on the page — highlight makes a translucent box, pen draws freehand. Move between pages to mark more, then click Save Annotated PDF. The marks are baked into a new file, so the PDF on your device is left as it was.
Can I annotate more than one page?
Yes — every page can carry its own annotations. Use the page selector to move through the document; each page keeps its own marks. All of them are baked into the final PDF when you save.
Can I undo a mark?
Yes — a mark can be undone. Undo removes the last mark on the current page, and Clear page wipes that page’s marks. Your original file is never changed — you only download a new copy.
Is my PDF uploaded?
No — the PDF stays on your device. Pages are rendered locally and the marks are drawn into the PDF in your browser with pdf-lib. Nothing is uploaded — closing the tab clears everything.
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