Annotate PDF
Highlight, box, note, and draw.
Runs in your browserIn: PDFOut: PDF
Runs in your browser — your file never leaves your device.
About this tool
Add highlight boxes, outlines, text notes, and lines or arrows onto a PDF. Markups are flattened into the page as vector content — all in your browser.
This tool processes files entirely on your device. Nothing is uploaded to a server.
How it works
- 1Open your PDF and pick a markup: highlight, box, note, or line.
- 2Place it by page and coordinates (PDF points from the bottom-left).
- 3Apply to flatten the markups in and download the annotated PDF.
What this tool can do
- Annotation kinds
- Six annotation kinds, including highlights, boxes, notes, and lines.
Common questions
Is my file uploaded when I use Annotate PDF?
No. This tool runs entirely in your browser with WebAssembly and browser APIs — the file stays on your device from start to finish.
Does Annotate PDF work offline?
Not fully — the page and its processing engine load over the network, with the engine fetched when you first use the tool. After that, the processing itself runs entirely on your device, and a dropped connection does not interrupt work in progress.
How large can my file be?
Up to 100 MB per file.
Related tools
All toolsNo sign-up required. Your files stay on your device until you run a tool.