Online Tool Store
PDF Annotator
Annotate a PDF with pen and highlighter tools directly on rendered pages, then save a flattened, downloadable PDF. Runs entirely in your browser.
🔒 This tool runs entirely in your browser. Your files are never uploaded to a server.
How it works
- Upload a PDF — each page renders as a real, readable image.
- Choose pen, highlighter, or eraser and mark up the page directly.
- Click "Save annotated PDF" to flatten your marks into a downloadable file.
FAQ
What annotation tools are available?
A pen for freehand marks, a highlighter (semi-transparent, thicker stroke), and an eraser to remove annotations on the current page — enough for marking up a document without a full PDF editor.
Do my annotations carry over between pages?
Each page keeps its own annotations — switching pages saves what you drew and restores whatever was already on the page you're navigating to.
Can I remove just one annotation?
The eraser removes ink where you drag it, like a physical eraser. "Clear this page" removes everything drawn on the current page in one click if you want to start over.
Is my PDF uploaded anywhere?
No — the PDF is rendered and annotated entirely in your browser, and the final file is assembled locally with pdf-lib. Nothing is sent to a server.
How we compare
| Feature | Online Tool Store | Full desktop PDF editors | Print, mark up, rescan |
|---|---|---|---|
| No install | ✓ | Requires a full application | ✓ |
| Stays a real, searchable PDF | ✓ | ✓ | Becomes a flat scanned image |
For a quick markup — circling a section, highlighting a clause — without installing a full PDF editor, this is faster and keeps the file private.