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PDF Editor

Watermark a PDF

Add diagonal text across every page. Control the size, angle and transparency before you download.

  • Free, no signup
  • No upload — runs on your device
  • No watermark
  • Unlimited use

Watermark PDF

Processed locally
Drop a PDF here

or click to browse

A watermark drawn on top is not a watermark that protects

This tool adds a new text object to each page's content stream, drawn last so it appears above your content. That is exactly what a watermark should do visually — and it is trivially removable by anyone with a PDF editor, because the watermark is a discrete object that can be selected and deleted. The same is true of every browser-based watermarking tool, and of most desktop ones.

Watermarks are a social control, not a technical one. They tell an honest reader that this is a draft, or that a document is not for circulation. If you need a mark that survives editing, it has to be composited into the page pixels — which means rasterising the document first, via the Compress PDF tool, and watermarking the result. You lose selectable text in exchange for a mark nobody can pick out with a click.

How it works

  1. Drop in the PDF
  2. Type your watermark text and adjust size, angle and opacity
  3. Click Apply and download the watermarked PDF
Why nothing uploads. Every operation on this page happens inside your browser using JavaScript and WebAssembly. Your file is read into memory, processed, and offered back as a download. It is never transmitted. Disconnect from the internet after this page loads and the tool keeps working.

Frequently asked questions

Can someone remove the watermark I add?
Yes, with a PDF editor. The watermark is a separate text object layered over the page, so it can be selected and deleted. To make it non-removable, rasterise the PDF first and watermark the images.
What opacity should I use so text stays readable?
Between 15% and 30% for a diagonal watermark over body text. Anything above 40% starts competing with the content; anything below 10% disappears on a phone screen.
Can I use an image or logo as the watermark?
Not in this tool — it stamps text only. For a logo, export a PDF page as an image, add the logo with the Watermark Image tool, and rebuild the PDF from images.
Does the watermark appear on every page?
Yes, on all pages, centred and rotated by the angle you set. Page-selective watermarking is not offered because in practice a partial watermark undermines the point of having one.
Will the watermark print?
Yes. It is part of the page content, so it prints exactly as it appears on screen, including its transparency.

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