Stamp text like COPY or "For visa application only" on every page. Nothing is uploaded.
The text is drawn on top of the page and is not a security feature: anyone with a PDF editor can remove it. Use basic Latin characters; others may not render. Password-protected PDFs must be unlocked first.
Is my PDF uploaded? No. The watermark is added locally in your browser.
Can I use a copy for a visa or bank? Writing COPY or the purpose on a document copy is common practice, but check what the receiving office accepts.
Why do some letters fail? The built-in font supports basic Latin letters only. Accented or non-Latin characters are rejected with a message.
Related: add page numbers, merge PDF, watermark an image.
Informational tool, not legal or tax advice.