Add Watermark to PDF

A watermark makes a document's status obvious at a glance: DRAFT on a contract under negotiation, CONFIDENTIAL on internal reports, SAMPLE on a design proof. It's also a common privacy habit when sending ID copies — stamping "Copy for XYZ rental application only" across a passport scan makes it much less useful if it ends up somewhere it shouldn't.

pdfdots places your text diagonally across the center of every page. The opacity slider controls how strong it looks: around 20–30% is visible without getting in the way of reading, while higher values make the mark more prominent and harder to ignore. Keep the text short so it fits comfortably across the page.

The watermark is added on top of the existing page content, so the original text stays selectable. Keep in mind that a text watermark discourages misuse but isn't tamper-proof; for strong protection, also compress or print-to-image the file. The whole process runs in your browser, which means the document you are protecting is never uploaded to anyone.

Watermarking works well together with other tools. For example, you can remove pages that aren't meant for the recipient, add the watermark, then compress the file so it's small enough to email. If you send the same document to several people, making a separate copy with each recipient's name as the watermark text makes it clear who each copy was intended for.