Add Watermark to PDF — Free Online
Updated September 2026
Add a text or image watermark to a PDF — adjustable position, size, color, opacity, and rotation. Browser-side processing, no server upload — free up to 5 pages, Pro removes the limit.
The PDF Watermark is a free online tool that add a text or image watermark to a pdf — adjustable position, size, color, opacity, and rotation. browser-side processing, no server upload — free up to 5 pages, pro removes the limit.
Add a text or image watermark to a PDF — adjustable position, size, color, opacity, and rotation. Browser-side processing, no server upload — free up to 5 pages, Pro removes the limit. Results are immediate — no waiting, no loading screens, no account required.
Who uses the PDF Watermark?
- Freelancers and designers watermarking short draft deliverables before client approval (within the free 5-page limit).
- Legal and HR teams marking confidential documents before distribution.
- Pro users watermarking longer contracts, reports, or document sets.
Common uses and search terms
The PDF Watermark is frequently used for: pdf watermark, add watermark to pdf, pdf stamp, watermark pdf online. Whether you need a quick result or are working through a longer project, the tool handles all common variations without any configuration.
Why use Allio Tools's PDF Watermark?
Everything runs locally in your browser. No data is sent to a server, logged, or stored anywhere. The tool is completely free with no usage limits, no premium tiers, and no account required. Available in 11 languages and optimised for all screen sizes, the PDF Watermark works on desktop, tablet, and mobile with no app download needed.
See also:PDF Split & Merge · Rotate PDF · PDF to Text
How the PDF Watermark works
Upload your PDF file.
Choose Text Watermark or Image Watermark mode.
For text: enter your watermark text, then adjust font size, color, opacity, rotation angle, and one of 5 fixed positions (center or a corner). For image: upload a PNG/JPEG logo and adjust its opacity, scale, and position.
Click Apply Watermark & Download. Free accounts can watermark PDFs up to 5 pages — Pro removes the limit.
Tips & tricks
- Position options are limited to 5 fixed spots (center + 4 corners) — there's no true tiled/repeat pattern across the page, despite what "tile the watermark" might suggest.
- The rotation slider defaults to -45° for a diagonal look, but this is a manual angle setting, not a labeled "Diagonal" preset — adjust it yourself between -90° and 90°.
- Free accounts are capped at 5 pages per PDF for watermarking — Pro removes this limit.
- Text and image watermarks are drawn directly onto the page content — they can later be removed with PDF editing tools like Adobe Acrobat Pro, they aren't tamper-proof.
Frequently Asked Questions
Can I add a diagonal watermark or tile it across the page?
There's no dedicated "diagonal" or "tiled/repeat" preset. You can manually set the rotation slider (default -45°) to angle the text, and the position dropdown offers center or one of four corners — but the watermark appears once per page, not repeated in a tiled pattern.
What is the best opacity for a PDF watermark?
For "DRAFT" or "CONFIDENTIAL" stamps: 30–50% opacity — visible but not obstructing content (30% is the default here). For subtle branding watermarks: 10–20%. For strong protection watermarks: 60–100%.
Is there a free page limit?
Yes. Free accounts can watermark PDFs up to 5 pages. PDFs longer than that require Pro.
Can I add an image or logo as a PDF watermark?
Yes. Switch to Image Watermark mode, upload a PNG or JPEG (transparent-background PNG recommended), and set its opacity, scale, and position (center or one of four corners).
Are my PDF files sent to a server?
No. PDF watermarking uses pdf-lib entirely in your browser — files are processed locally on your device.
Is my data safe when using the PDF Watermark?
Completely safe. The PDF Watermark processes everything locally in your browser. No input data, results, or usage information is ever transmitted to or stored on any server.
Can I use the PDF Watermark on my phone or tablet?
Yes. The PDF Watermark is fully responsive and works on all modern smartphones and tablets. No app download is required — open your mobile browser, navigate to the tool, and use it exactly as you would on a desktop.
How do I share the PDF Watermark results?
Copy the result text or take a screenshot to share via message, email, or social media. The tool URL can also be bookmarked and shared directly — the PDF Watermark works for anyone with a modern browser, no account required.
Works with ChatGPT, Claude, Cursor, GitHub Copilot, VS Code, Poe and more — 106+ tools, zero data collection.