Watermark PDF

What is Watermark PDF?

Watermark PDF is a free, browser-based tool that stamps a text or image watermark onto the pages of a PDF. Place it at any of nine positions with a margin, or tile it diagonally across the whole page. Control the text, opacity, font size, rotation angle, and color; by default the built-in font covers Latin (ASCII) text, but you can upload a .ttf/.otf font to render CJK and other Unicode scripts without dropping any characters. You can also stamp a PNG or JPG logo with its own size and opacity, restrict the watermark to a page range like 1-3,5, and see a live preview of the stamped first page. Everything runs with pdf-lib entirely in your browser, so the document is never uploaded.

How to use Watermark PDF

1. Drag and drop a PDF onto the dropzone (or click to choose a file). The tool shows the page count and a first-page preview.
2. Type your watermark text, and/or drop a PNG/JPG logo to stamp an image instead of or alongside the text.
3. Pick a position (one of nine anchors) with a margin, or open Settings and switch Repeat to Tiled to cover the page diagonally.
4. In Settings, adjust opacity, font size, rotation, and color, set a page range like 1-3,5, and — for CJK/Unicode text — upload a .ttf/.otf font.
5. Watch the live preview update, then click Download to save the stamped PDF as <name>-watermarked.pdf.

Examples

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?

Yes. By default the watermark uses a built-in font that only covers Latin (ASCII) characters, so non-Latin text is not drawn and you are warned instead of losing characters silently. To render Chinese, Japanese, Korean, or other Unicode text, upload a .ttf/.otf font in Settings and it is embedded (as a subset) into the PDF.

Which pages get the watermark?

By default every page. You can restrict the watermark to specific pages with a page range such as 1-3,5 in Settings; leave it empty to stamp all pages.

What can I adjust?

The text, opacity, font size, rotation angle, and color, plus a 9-position placement with a margin — or diagonal tiling. You can also stamp a PNG/JPG logo with its own size and opacity. 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.