Watermark PDF

Stamp a text watermark on every page of a PDF in your browser, with adjustable opacity, font size, rotation angle, and color, no upload needed.

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Watermark PDFAdd a repeating text watermark — like CONFIDENTIAL or DRAFT — across every page of a PDF. Choose the opacity, font size, rotation angle, and color, then download the stamped file. Everything runs with pdf-lib entirely in your browser, so the document is never uploaded.

What is Watermark PDF?

Watermark PDF is a free, browser-based tool that stamps a single line of text diagonally across the center of every page of a PDF. It is used to mark documents as CONFIDENTIAL, DRAFT, SAMPLE, or COPY, to add a name or notice, or to brand reports and contracts before sharing them. You control the watermark text, its opacity, font size, rotation angle, and color, and a clickable first-page preview shows the original before you stamp it. The watermark is drawn with the standard Helvetica font, so it supports Latin (ASCII) text only — CJK and other non-Latin scripts are not rendered.

How to use Watermark PDF

  1. Drag and drop a PDF onto the dropzone (or click to choose a file). The tool loads it and shows the page count plus a first-page preview you can click to enlarge.
  2. Type your watermark text (for example CONFIDENTIAL) in the Watermark text field. Use Latin characters — non-Latin text like Chinese, Japanese, or Korean is skipped.
  3. Open Settings to adjust the opacity (0–100%), font size, rotation angle in degrees, and color of the watermark.
  4. The preview and output rebuild as you type and tweak settings; the watermark is drawn centered and rotated on every page.
  5. Click Download to save the stamped PDF as <name>-watermarked.pdf.

Examples

Mark a contract as CONFIDENTIAL

Drop contract.pdf, type CONFIDENTIAL, set opacity to 20% and rotation to 45°, and download. Every page gets a faint gray diagonal CONFIDENTIAL stamp across its center, saved as contract-watermarked.pdf.

Add a bold DRAFT stamp

For a 12-page report, type DRAFT, raise the font size to 72 and opacity to 35%, and pick a red color. All 12 pages receive the same large red DRAFT watermark rotated 45 degrees.

Horizontal SAMPLE label

Set rotation to 0 to lay the text flat instead of diagonal. Typing SAMPLE produces a level watermark centered on each page — useful for catalog or proof pages.

Frequently asked questions

Is my PDF uploaded to a server?
No. Everything runs 100% client-side in your browser using pdf-lib. Your document is read and stamped locally and is never uploaded, so it stays private even for confidential files.
Can I use Chinese, Japanese, Korean, or other non-Latin text?
No. The watermark is drawn with the standard Helvetica font, which only covers Latin (ASCII) characters. Non-Latin characters are skipped, so the watermark text must use Latin letters, digits, and basic punctuation.
Which pages get the watermark?
Every page. The same text is stamped, centered and rotated, on all pages of the document at once. There is no per-page selection.
What can I adjust?
The watermark text, its opacity (0–100%), font size, rotation angle in degrees (0 lays it flat, 45 makes it diagonal), and color. The preview and download update as you change these.
Can the watermark be removed later?
The text is drawn into the page content, so it isn't a simple metadata tag — but like most printed-on watermarks it isn't tamper-proof and could be edited with PDF software. Use it as a notice, not as hard security.

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