Watermark PDF
Add a permanent text watermark — like “CONFIDENTIAL”, “DRAFT” or your name — across a PDF. The watermark is drawn diagonally across the full page, with a density and opacity you control. It's baked into the file itself, so it persists in every viewer and printer. Everything runs locally with pdf-lib in your browser.
Your files never leave your device. All processing happens on your device. No uploads, ever.
How to use Watermark PDF
- 1
Choose a PDF
Upload the document to watermark.
- 2
Type the watermark
Enter the text you want stamped on every page.
- 3
Fine-tune
Adjust opacity, size and how many stamps appear.
- 4
Watermark & download
Get your stamped PDF instantly.
Text that's baked in
The watermark is drawn directly into the PDF using an embedded font, so it shows up in any viewer, editor or printout — it's baked in, not just a preview.
Tune opacity & density
Two sliders let you decide how subtle or prominent your watermark is across the diagonal.
Private by design
Watermarks are stamped locally in your browser. Your PDF is never uploaded anywhere.
Frequently asked questions
Is the watermark visible everywhere?
Yes. It's drawn directly onto the page — it appears in Preview, Acrobat, browsers, and printouts.
Can I make it subtler?
Use the opacity slider. Lower values keep the paper readable while still marking it.
Is my file uploaded?
No. The PDF never leaves your browser during watermarking.
More pdf tools
Images to PDF
Client-SideTurn JPG, PNG and WebP images into a single PDF in seconds. Choose page size and layout — all in your browser, nothing uploaded.
Compress PDF
Client-SideShrink PDF file size for email and the web. Compression runs entirely in your browser — pick a level, download the smaller file, nothing uploaded.
Merge PDF
Client-SideCombine two or more PDFs into one document in seconds. Reorder the files any way you like — all done in your browser, nothing is uploaded.
PDF Page Manager
Client-SideReorder, delete and tidy PDF pages visually — then download the cleaned document. Runs entirely in your browser, nothing uploaded.
Protect PDF
Client-SidePassword-protect a PDF with strong AES-256 encryption, right in your browser. Your document and password never leave your device.
Rotate PDF
Client-SideTurn PDF pages 90°, 180° or 270° in one click — the whole document or specific pages only. Runs in your browser, nothing uploaded.
Related tools
Protect PDF
Client-SidePassword-protect a PDF with strong AES-256 encryption, right in your browser. Your document and password never leave your device.
Compress PDF
Client-SideShrink PDF file size for email and the web. Compression runs entirely in your browser — pick a level, download the smaller file, nothing uploaded.
Rotate PDF
Client-SideTurn PDF pages 90°, 180° or 270° in one click — the whole document or specific pages only. Runs in your browser, nothing uploaded.
PDF Page Manager
Client-SideReorder, delete and tidy PDF pages visually — then download the cleaned document. Runs entirely in your browser, nothing uploaded.
Last updated 8 August 2026