Need to stamp 'CONFIDENTIAL' on a draft contract? Mark a proposal as 'DRAFT' before sharing? Brand a portfolio with your name? This free PDF watermark tool overlays your chosen text across every page — diagonally, centred, or in a header/footer — directly in your browser. Choose the color, opacity, and size. No upload, no watermark from us, no sign-up.
A PDF watermarker overlays text on every page of a PDF as a translucent stamp. The most common use is a legal-style 'CONFIDENTIAL' or 'DRAFT' marker running diagonally across each page. Unlike server-based tools that upload your file, this tool uses pdf-lib running in your browser. We embed Helvetica Bold, compute the geometry for your chosen position and rotation, and draw the text on top of each page at the opacity you select.
100% client-side processing — your PDF never leaves your browser. Four positions: diagonal, center, top, or bottom. Custom text (any length). Custom font size, color, and opacity (1–100%). Diagonal mode auto-calculates the page-diagonal angle. Helvetica Bold for crisp visibility. Lossless — original page content is preserved. No watermarks from us, no ads, no sign-up. Works on mobile and desktop.
When you drop a PDF, the tool parses it with pdf-lib. You enter the watermark text and configure position, color, opacity, and font size. On click, the tool embeds Helvetica Bold, iterates the pages, and for each one: measures the text width at the chosen size, computes the (x, y) position based on the page dimensions and your selected anchor, computes the rotation angle (the page diagonal for 'diagonal' mode, zero otherwise), and draws the text at the chosen color and opacity. The watermarked PDF is re-saved and offered as a download via an in-browser blob URL. Nothing is sent to a server.
Legal contracts — stamp 'DRAFT' or 'CONFIDENTIAL' before circulating for review. Internal reports — mark 'INTERNAL USE ONLY' before sharing with consultants. Photography portfolios — overlay your name across sample work to deter casual theft. Tender responses — mark proposals 'COMMERCIAL IN CONFIDENCE'. Educational handouts — add your school or course name to every page. Sample documents — stamp 'SAMPLE' or 'PREVIEW' before publishing a teaser version.
Privacy first — most online watermark tools upload your file. We don't. Watermarking runs entirely in your browser, which matters for sensitive contracts, financial reports, and pre-publication content. Speed — no upload, no queue. Most files are watermarked in under a second. Flexible — any text, any color, any opacity, four positions including a true page-diagonal. Lossless — the original page content is untouched. Free forever — no premium tier, no email gate.
Lawyers stamping drafts and confidential exhibits. Consultants and agencies marking proposals as 'COMMERCIAL IN CONFIDENCE'. Photographers and designers branding portfolio PDFs. Authors and publishers marking pre-release samples. HR teams marking internal handbooks. Anyone who needs to brand or warn-label a PDF before sharing it.
Drop your PDF, type your watermark text (e.g. 'CONFIDENTIAL'), pick Diagonal position, set color to red and opacity to 25%. Click Add Watermark — done. Download the file as '
Diagonal + 25% opacity + red is the classic legal-style watermark — it reads clearly without obscuring the underlying content. For internal documents where readability matters most, use bottom-center at 50% opacity and dark gray. Keep the text short (one or two words) for diagonal mode so it doesn't overflow the page. For maximum deterrence on visual content (portfolios, photo PDFs), bump opacity to 50% and use a contrasting color.
Text watermarks only — image/logo watermarks coming soon. Watermarks can be removed by users with PDF editing tools — this is a deterrent, not DRM. Cannot apply different watermarks to different pages — every page gets the same text. Strong-password-protected PDFs need to be unlocked first using our PDF Password Remover.
Yes. No sign-up, no watermark on our output (only yours!), no limits.
No. Watermarking happens locally with pdf-lib. Your PDF never touches our servers — verify with DevTools → Network.
The text runs from the bottom-left corner to the top-right corner of each page, rotated at the page's diagonal angle. It's the classic 'CONFIDENTIAL' stamp look used in legal and corporate documents.
Not easily by a normal user. The watermark is drawn into the page content stream, so removing it requires editing the PDF's internals. For sensitive documents, this is usually 'good enough' protection — but a determined attacker with PDF editing tools can strip it. Use real DRM if you need true protection.
Watermarks are drawn on top of the page at the opacity you choose. At 20-30% opacity, the underlying text and images remain fully readable. At 100% opacity, the watermark fully blocks whatever is behind it.
Not yet — this tool currently supports text watermarks only. Image watermark support is on the roadmap.
No. The watermark is added as a new drawing layer on top of every page. The original page content (fonts, images, hyperlinks) is preserved exactly.
Up to 100MB per file. The watermark itself adds only a tiny amount to the file size.
See also: Add Page Numbers to PDF, Merge PDF, PDF Password Remover.