Add Watermark to PDF
Stamp a text watermark like DRAFT or CONFIDENTIAL across a PDF, with control over opacity, colour and angle.
Quick answer: Add Watermark to PDF: stamp a text watermark like DRAFT or CONFIDENTIAL across a PDF, with control over opacity, colour and angle. Runs entirely in your browser, free, no signup.
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A watermark's job is to signal status or ownership without hiding the content underneath, so opacity is the setting that matters most. Around 25–30% is the practical sweet spot: clearly legible as a DRAFT or CONFIDENTIAL stamp, yet transparent enough that the reader can still work through the page. Push it toward 100% and you have obscured the very document you are trying to circulate.
The classic diagonal — a 45-degree stamp running across the center — is popular for a reason: it crosses the natural reading path, so it cannot be ignored or cropped out of a screenshot as easily as a corner mark. The Pages field lets you target a range like 1-3, 5 when only certain pages need flagging, which is handy for stamping a cover sheet or a specific exhibit rather than the whole file.
One important limitation: this is a visual deterrent, not security. The mark is drawn into the page but it does not lock, encrypt or prevent editing — a determined recipient can still remove it. If your goal is to keep versions or exhibits organized rather than to protect them, pairing the watermark with page numbers makes a document far easier to reference in a meeting.
Frequently asked questions
- How do I add a watermark to a PDF?
- Drop the PDF, type the watermark text (e.g. DRAFT), pick a position and adjust opacity / colour / size, then click Download watermarked PDF.
- Can I watermark only some pages?
- Yes. Type a page range like 1-3, 5 in the Pages field. Leave it blank to apply the watermark to every page.
- Can I change the watermark opacity?
- Yes. The opacity slider goes from 5% (barely visible) to 100% (solid). 25-30% is the sweet spot for most documents.
- Can I rotate the watermark?
- Yes. Use the rotation slider to set any angle from -90° to +90°. The classic look is a 45° diagonal stamped across the centre.
- Does it work on scanned PDFs?
- Yes. The watermark is drawn on top of the existing page content, whether that content is text or a scanned image.
- Will it increase file size?
- Only marginally. The watermark is a few text-drawing operators per page — typically a few KB total, regardless of the watermark size.
- Is it secure?
- Yes. Your PDF never leaves your device — watermarking happens entirely in your browser.
- Are files stored?
- No. Both the original and the watermarked PDF exist only in your browser tab.
- Can I watermark PDFs on mobile?
- Yes. Works in mobile Safari and Chrome.
- Is it free?
- Yes — completely free, no signup, no watermark on the watermarker.