Add a watermark to a PDF

Why watermark your PDFs with ModySign?

Watermarks are one of the most important visual signals inside a company: they make it clear that a document is confidential, a draft, internal, or awaiting approval. Without a watermark, a draft contract can be mistaken for the final version, a draft can be signed by accident, or an internal note can leak by mistake.

Most online PDF watermark tools upload your document to their foreign servers, which rules them out for a confidential contract or a sensitive folder. ModySign applies the watermark directly in your browser thanks to pdf-lib — no upload, no server trace, zero leak risk.

Three placement modes are available: "Centre" (a single watermark in the middle of the page), "Diagonal" (a large 45° watermark in the centre, ideal for CONFIDENTIAL or DRAFT), and "Tiled" (the text is repeated across the whole page, perfect for an internal-only document).

Questions fréquentes

Can I pick the watermark colour and opacity?+

Yes. Three colours are available (grey, red, blue) and opacity is adjustable between 10% and 50%. A 30% grey watermark stays readable without hiding the content — that's the default.

Is my PDF uploaded to your servers?+

No, never. Watermarking runs entirely in your browser via pdf-lib. Your file never leaves your machine — unlike Smallpdf, iLovePDF or Sejda, which upload your documents to their foreign servers.

Is the watermark easy to remove?+

The watermark is added as a text layer in the PDF. A determined user can technically edit it out with a professional PDF tool. For strong (un-removable) protection, rasterise the PDF into images after watermarking — you can do that by piping the result through our compressor tool.

Can I watermark every page of a PDF at once?+

Yes. The watermark is automatically applied to every page in the PDF. That's what people actually expect from a "CONFIDENTIAL" mark — present everywhere, not just on the cover.