Add Watermark to PDF
Add text as a watermark to your PDF. 100% in your browser.
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How adding watermark works with puduPdf
puduPdf adds watermarks to your PDF using page.drawText() from pdf-lib with StandardFonts.Helvetica font. Text is automatically centered on each page using font.widthOfTextAtSize() to calculate exact coordinates. Opacity and rotation are applied as rendering parameters. All processing is 100% local.
How to add a watermark to a PDF for free
- 1
Upload your PDF
Drag or select the PDF file to which you want to add a watermark.
- 2
Configure the watermark
Enter the desired text and adjust font size, opacity (transparency) and rotation angle.
- 3
Download the result
Click 'Add watermark' and download your PDF with the watermark applied to all pages.
Key features
- Customizable text with adjustable font size using Helvetica from pdf-lib
- Opacity control (transparency) so the watermark doesn't hide the content
- Configurable rotation to position the watermark diagonally or horizontally
- Auto-centering using font.widthOfTextAtSize() for precise position calculation
Frequently Asked Questions about Watermark
Everything you need to know about adding watermarks
Can I customize the watermark?
Yes. puduPdf lets you configure the text, font size, opacity (transparency) and rotation angle. Text is rendered with page.drawText() from pdf-lib using the Helvetica font, and automatically centered on each page using font.widthOfTextAtSize() to calculate the exact position.
Is the watermark applied to all pages?
Yes. puduPdf iterates over each page of the document and applies the watermark with the same text, size, opacity and rotation settings. Centering is calculated individually for each page, adapting to pages of different sizes within the same PDF.
Can the watermark be removed afterwards?
The watermark is drawn directly on each page's content using drawText() from pdf-lib. Once applied, it becomes part of the PDF and cannot be easily removed. We recommend keeping your original PDF without watermark as a backup. All processing is local, so your original file is never modified.