Watermark PDFs on your computer

Stamp a diagonal text watermark (confidential, draft, copy...) on every page, with live preview. The stamp uses the Latin alphabet. Free, and no file ever gets uploaded to a server.

100% private: everything runs on your computer, your files never leave your device.

  1. Upload your PDF - it opens locally on your computer
  2. Configure text, opacity and size with live preview
  3. Save the watermarked PDF

What Watermark PDF does

Watermark PDF stamps a semi-transparent text, or a PNG or JPG image, on every page of a document. You type the text or pick the picture, set the opacity, size, position and rotation while a live preview shows the result, and OléPDF writes the watermarked file in your browser. The pages themselves are copied as vector objects, so text stays selectable and nothing is turned into an image.

It is the quickest way to mark a document's status or ownership before it leaves your hands: a contract draft labelled DRAFT, a report marked CONFIDENTIAL, a copy of an invoice stamped PAID, a portfolio with a logo across each page. There is no upload, no account and no daily limit.

How to add a watermark to a PDF

  1. Add the PDF. It opens in the page review screen and the Watermark panel appears on top of it.
  2. Choose Text or Image. In text mode type up to 60 characters, or pick one of the quick stamps: DRAFT, CONFIDENTIAL, URGENT, PAID, APPROVED or COPY. In image mode choose a PNG or JPG from your device.
  3. Adjust Opacity, from 5 to 50 percent, Size, Rotation from 0 to 360 degrees, and Position on a three by three grid. The preview page and the thumbnails update as you move the sliders.
  4. Press Apply. You can still reorder, rotate or exclude pages in the review screen, or reopen the panel to change or remove the watermark.
  5. Press Save PDF. The file downloads with the suffix _watermarked and a timestamp.

Defaults, options and limits

The defaults are chosen for the classic diagonal stamp: text CONFIDENTIAL, 18 percent opacity, 45 degrees, centred, with a size that spans a good part of the page diagonal. Images start at 0 degrees and half the page width. Both kinds of watermark keep their proportions and are placed so that a corner position stays in the corner even after rotation.

Privacy: the watermark is stamped on your computer

The preview thumbnails are rendered by the PDF engine bundled with OléPDF and the new file is written by a local PDF library, both running in your browser tab. The document is never uploaded, the image you choose for the watermark is read from your disk and never transmitted, and no third-party script is loaded. The only download is OléPDF's own code from its own domain.

That makes it safe to stamp contracts, financial statements or any document whose content is the reason you want it marked in the first place.

Typical uses

Frequently asked questions

Is adding a watermark free?

Yes. Watermarking is free and unlimited, with no account, no daily cap and no OléPDF branding printed on the pages.

Can I use a logo instead of text?

Yes. Switch the panel to Image and choose a PNG or JPG. PNG files with transparency keep it, so a logo with a transparent background sits cleanly over the content.

Can I change the colour of the text watermark?

No. The text is always light grey; opacity, size, rotation and position are adjustable. For a coloured mark, use an image.

Can the watermark be removed later?

Not by a reader of the document. It is drawn into the page content, not added as a removable annotation. Keep your original if you need a clean copy.

Does watermarking reduce the quality of the PDF?

No. Pages are copied as vector objects and the watermark is drawn on top; text, fonts and images remain exactly as they were.

Can I apply the watermark to some pages only?

Not in this tool: it is applied to all pages. Split the PDF, watermark the part you need and merge the files back if only certain pages should carry it.

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