Helpful Toolbox

Watermark PDF

Stamp a diagonal, see-through text watermark across every page of your PDF — private, instant, and free.

📖 How it works & FAQ

Add a repeating diagonal text watermark to every page. Your file is processed entirely in your browser and never uploaded.

Watermark your PDF without uploading it

A watermark is a light, angled label stamped across a page — words like DRAFT, CONFIDENTIAL, SAMPLE, or your name. It signals status or ownership without hiding the underlying content. This tool draws your chosen text diagonally across every page of a PDF at the opacity and size you pick, then hands you a new file to download. The whole thing runs in your browser using pdf-lib, so the document you select is never sent to a server — it stays on your device the entire time.

Choosing text, opacity & size

Short, all-caps words read best when rotated 45 degrees across a page. Keep opacity low — somewhere around 0.15 to 0.35 — so the watermark is clearly visible yet the text beneath stays readable. Larger font sizes make a bolder single stamp; on very wide or very tall pages you may want to nudge the size up so the label spans more of the page. Gray is the most neutral choice, while red reads as a stronger warning for drafts and confidential material.

How to use it

  1. Click PDF file and choose the document you want to mark.
  2. Type your watermark text (for example, CONFIDENTIAL).
  3. Drag the Font size and Opacity sliders to taste.
  4. Pick a color from the dropdown.
  5. Press Add watermark & download and save the new file.

FAQ

Is my PDF uploaded anywhere?
No. Everything happens locally in your browser. Your file never leaves your device, which makes this safe for private or sensitive documents.
Does it watermark every page?
Yes. The same diagonal watermark is drawn on all pages, and the download message confirms the page count.
Can the watermark be removed later?
The text is drawn into the page content, so it can't be toggled off in a normal viewer — but it's not encryption or true copy protection. Keep your original file if you'll need a clean copy.
Why does my watermark look off-center?
The label is centered for standard portrait pages. On unusual page shapes, adjust the font size so it fits, then regenerate.