Whether you're reviewing a contract, marking up a report, or giving feedback on a design, you can annotate a PDF directly in your browser without any software.
Navigate to pdfeditor.onl/pdf-studio and upload the PDF you want to annotate.
Select the Pen/Annotation tool from the toolbar. Choose your pen colour and thickness, then draw directly on the page. This is useful for circling items, drawing arrows, or sketching corrections.
Use the Text tool to click anywhere on the page and type a note. Change the font colour to red or another accent colour to make comments stand out clearly against the document content.
Tip: Use a small font size (8–10pt) for margin notes and a larger size for prominent comments that need to stand out.
Click Download PDF. All annotations are permanently embedded in the output file and will be visible to anyone who opens it.
Yes. The drawing tool works with stylus input on iPad (Apple Pencil), Samsung tablets (S Pen), and other active stylus devices.
The annotations are flattened into the PDF page content, which means they appear as permanent visual elements. They cannot be selected or moved by the recipient in a standard PDF viewer.
Yes — all annotation tools in PDF Studio are completely free with no account or limits.