scriptiii
100% Client-Side

Real page content, not an annotation

Add a watermark to a PDF

Write text across every page — DRAFT, CONFIDENTIAL, a client name — at whatever size and opacity keeps the page readable.

The stamp is drawn in this browser tab. Your document is never uploaded.

Short answer: type the text, pick a size and an opacity, then press “Watermark and download”. Every page gets the stamp as real content, so it prints and survives forwarding. 15% diagonal is the usual setting for a readable page.

Why opacity matters more than the words

A watermark people cannot read past gets the file rejected; one nobody notices does nothing. Light grey at 10–20% behind the text keeps every word legible and still marks the page. Long text is shrunk to fit the diagonal rather than running off the edge.

What a watermark does and does not do

It records where a copy came from and discourages casual reuse. It does not stop anyone from copying the file, and it is not encryption. If the document must not be opened by the wrong person, the honest answer is a password, not a stamp — this page will not pretend otherwise.

Watermark questions

Is the watermark real page content?

Yes. The text is drawn onto each page with an embedded font, so it prints, survives a copy and cannot be switched off in a viewer the way a comment or an annotation layer can.

Can I use Hindi or another non-Latin script in the watermark?

Not yet. The built-in PDF fonts cover Latin characters, so a stamp in Devanagari is refused with a message instead of being written as question marks. Latin text, digits and common punctuation work everywhere.

How faint should the watermark be?

Around 10–20% opacity keeps the page readable while still marking it. For a “DRAFT” or “CONFIDENTIAL” stamp on documents people must read, 15% diagonal is the usual choice; for a proof mark, go higher.

Does a watermark stop someone copying the file?

No, and no watermark does. It marks provenance and deters casual reuse. If the document must not be read by someone, encrypt it with a password instead — that is a different operation.

Related tools

Add page numbersNumber the pages while you stamp them.Merge PDFsCombine documents, then stamp the result.Split PDFSend only the pages that need the stamp.