Add a watermark to a PDF

Add a watermark to a PDF in seconds: drop in the file, type text such as “CONFIDENTIAL” or “DRAFT” or choose a logo, set position and opacity – the preview shows the result right away. Everything happens in your browser; the file is never uploaded.

Source: Adobe – ISO 32000-1:2008 Document management – Portable document format (PDF 1.7). Updated: 30 September 2026.

How it is calculated

A watermark shows at a glance how a document should be treated: “CONFIDENTIAL”, “DRAFT”, “COPY” or “For rental application only”. When you send copies of IDs or pay slips, stating what they are for is widely recommended to make misuse harder. Your company logo on quotes or drafts works the same way.

How it works

Drop in the PDF. The preview shows the first affected page.
Type your text and pick a color – or switch to “Logo / image” and choose a PNG or JPG (transparent PNGs look best).
Position: centered (with any angle, 45° = diagonal), tiled across the whole page or small in a corner.
Set size and opacity; 20–30% keeps the text underneath easy to read.
Optionally limit it to certain pages, e.g. “1” or “2-5”. Then click “Add watermark”.

Technology and fonts

The watermark text is drawn in your browser with a system font into a transparent image, which is then placed into the PDF. That way every script works – accents, Cyrillic, Japanese – and the watermark cannot simply be selected and deleted as text. Opacity is set through the PDF graphics state (ISO 32000-1, 11.6.4.4). Rotated pages and shifted page boxes are taken into account.

Honest limits

A watermark is a visible notice, not copy protection: a determined person can remove it with PDF software or photograph the page.
“Place behind the page content” only works for PDFs with real text. A scanned page is one single image that would cover the watermark – there it stays in front.
Password-protected PDFs cannot be edited; digital signatures become invalid.

To watermark photos instead of PDFs, use Add watermark to photos. To add page numbers: Add page numbers to PDF.

Frequently asked questions

How do I add a watermark to a PDF?

Drop your PDF in here, type text or choose a logo, set position and opacity and click “Add watermark”. Free and without upload.

How do I put a diagonal “CONFIDENTIAL” on every page?

Text “CONFIDENTIAL”, position “Center”, angle 45° – that is the default. Leave “Pages” empty and every page gets the watermark.

Can I use my logo as a watermark?

Yes, switch to “Logo / image” and choose a PNG or JPG. A PNG with a transparent background looks cleanest.

Can the text under the watermark still be read?

Yes, with 20–30% opacity the content stays easy to read. For text PDFs you can also place the watermark behind the content.

Can a PDF watermark be removed?

With effort, yes – a watermark is not technical protection. But it makes clear what a document is meant for and discourages misuse.

Is my PDF uploaded?

No. The watermark is created and added entirely in your browser.

Sources and legal basis

As of: 30 September 2026