Loona Add Watermark to PDF Online - Free
A watermark marks ownership and status at a glance: drafts stay drafts, and your institution's name travels with the document. Type your text, tune how bold or faint it looks, and download a stamped copy.
How to add a watermark to a PDF
- Choose the PDF to stamp.
- Type your watermark text and set size, opacity, angle, colour and layout (single centre stamp or tiled).
- Click "Add Watermark" and download the stamped PDF.
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Frequently Asked Questions
Can a watermark be removed later?
Watermark text is drawn into each page like regular content. It is not a security lock - for true protection, a password-protected PDF is the right tool.
What opacity should I use?
Around 0.15-0.25 keeps the stamp clearly visible without hiding the page content. Lower is subtler; higher makes a bold statement.
What does the tiled layout do?
Instead of one stamp in the centre, the text repeats in a grid across the whole page - harder to crop out.
Are my files uploaded?
No. The watermark is applied in your browser only.
How it works
Your PDF is opened locally in the browser with pdf-lib - it is never uploaded - and the tool embeds the Helvetica Bold font and stamps your text onto every page, drawn over the existing content. You control the size (24 to 60 pt), the tilt (flat, 30, 45 or 60 degrees), the colour (gray, red, blue or black) and the strength with the opacity slider, from a faint 0.05 up to a firm 0.6. In centre layout one stamp sits in the middle of the page; in tiled layout the stamp repeats in a grid across the whole page. The result downloads as a new file with -watermarked in its name.
Worked example
A freelancer is sending a 12-page design proposal to a new client and wants to protect it before payment. She types DRAFT, picks the tiled layout at 48 pt, a 45-degree angle, gray colour and 0.20 opacity. Every page of the downloaded proposal-watermarked.pdf carries a repeating diagonal DRAFT pattern that reads clearly but never hides the design underneath.
Frequently asked questions
Is the watermark stamped over or under the page content?
Over. The text is drawn after the page's own content, so it stays visible on top of text, images and scans alike - exactly what a watermark is for.
Can I watermark only a few selected pages?
No - the stamp is applied to every page of the document, which is normally what you want for a status mark like DRAFT or CONFIDENTIAL. To protect just one section, extract those pages first and watermark the extracted file.
Can I use my logo or a picture as the watermark?
Not in this tool - it stamps text in Helvetica Bold. If your logo exists as a one-page PDF, a similar effect is not possible here; a short text version of your brand name is the practical option.
Does the watermark show when the document is printed?
Yes. The stamped text is real page content, so it prints exactly as it appears on screen, at the opacity you chose - one more reason to keep opacity modest for documents that will be read on paper.
Can I type watermark text in Urdu, Arabic or Chinese?
The built-in Helvetica font covers standard Latin letters, numbers and common symbols only, so scripts such as Arabic or Chinese characters cannot be stamped. English text like CONFIDENTIAL or a company name works reliably.
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