PDF Watermark
Stamp a custom text watermark on your PDF — choose font, color, position and opacity.
Drag & drop a PDF file here
or click to browse
What is PDF Watermark?
A PDF watermark tool stamps a repeating or single text label over every page of a PDF document, giving you a fast way to mark files as confidential, draft, approved, or branded with your organisation name. Unlike image-based watermarking, text watermarks remain sharp at any zoom level and add minimal file size overhead because they are rendered as vector text directly into the PDF page content stream.
This tool gives you full control over the visual appearance of the watermark. You can set the text string, choose font size, pick any CSS color or use a hex value, adjust opacity from fully transparent to fully opaque, and select from a diagonal, horizontal, or centered placement. Diagonal watermarks are the most common choice for confidentiality marking because they span the full page and are hard to crop away. Centered watermarks work well for single large stamps like "APPROVED" or a company logo replacement.
The entire process runs in your browser using pdf-lib, so your documents never leave your device. This makes the tool safe to use with sensitive legal, financial, or personal documents. Output PDFs retain all original text, fonts, embedded images, and hyperlinks from the source document — only the watermark layer is added on top of the existing page content.
How to Use PDF Watermark
- Upload your PDF
Click or drag and drop to select the PDF file you want to watermark.
- Enter watermark text
Type your watermark text such as "CONFIDENTIAL", "DRAFT", or your company name.
- Customise appearance
Set font size, color, opacity, and position — diagonal, horizontal, or centered on each page.
- Apply and download
Click "Apply Watermark" and download the stamped PDF. Every page will carry the watermark.
Key Benefits
pdf-lib processes everything in your browser — no file is ever sent to a remote server.
Adjust text, size, color, opacity, and placement independently for the perfect look.
The watermark is stamped consistently on all pages in a single pass, no matter the page count.
Original text, images, hyperlinks, and fonts are untouched — only the watermark layer is added.
Frequently Asked Questions
Watermarks added by this tool are embedded in the page content stream. They can be edited with a PDF editor like Adobe Acrobat but cannot be automatically removed by a simple tool.
An opacity of 20-30% produces a light, professional watermark that is clearly visible without obscuring the underlying content.
Not directly. Use the PDF Password Remover to unlock the file first, then apply the watermark here.
Yes. The tool calculates the page dimensions and centers or angles the watermark relative to each page's actual size.