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Open one PDF
Choose or drop a document and navigate previews of each visible page area.
Private focused PDF editor
Add a watermark to every PDF page privately.
Add text or an image watermark to selected PDF pages while the source and watermark asset stay in your browser. You can preview placement, opacity, size, rotation, and tiling before downloading a separate watermarked PDF. Adding visible content can invalidate digital signatures, and portfolios, advanced forms, scripts, or viewer-specific features should be reviewed in the finished copy.
Add PDF watermark workspace
Drop one PDF here
Add a text or image watermark across one page or the whole document. Files, previews, and output stay in this browser tab.
Nothing is uploaded
No upload, account, or product watermark
PdfEditorOnlineFree opens the source, decodes an optional image, renders previews, writes the watermark into the page content, saves, and reopens the output with the result on this device. Your original file is never overwritten.
How to watermark a PDF
Start with a useful default, then tune only what matters.
The reference preset is CONFIDENTIAL in gray at 48 pt and 15% opacity, repeated diagonally with 200 px horizontal and vertical spacing.
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Choose text or image
Use CONFIDENTIAL, DRAFT, COPY, copyright text, custom Latin text, or a common image format.
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Set pattern and style
Choose Single Center, Diagonal Tiled, or Grid, then adjust opacity, size, color, placement, and spacing.
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Validate and download
Apply to the current page or all pages; the saved PDF is reopened and checked before download.
Mixed pages stay page-aware
Placement is measured inside each visible page area and transformed through its page rotation, so portrait, landscape, rotated, and mixed-size pages follow the preview direction.
Image transparency is preserved
Browser-decoded pixels retain their alpha channel, which is then combined with the selected watermark opacity. Very large images are reduced for a practical watermark resource.
Review signed or specialized PDFs
Adding visible content can invalidate cryptographic signatures. Portfolios, scripts, advanced forms, and viewer-specific features should be reviewed in the downloaded copy.
Frequently asked questions
Practical answers before you stamp the document.
Does PdfEditorOnlineFree upload my document or image?
No upload occurs. PDF bytes, image bytes, previews, watermark objects, validation, and the downloadable result remain in this browser tab.
Can I watermark only one page?
Yes. Choose Current page for an exception or All pages for the usual document-wide watermark.
Which image formats can I use?
Current Chromium, Safari, and Firefox releases commonly decode JPEG, PNG, WebP, GIF, BMP, and AVIF. Browser codec support can vary.
Why is custom text limited to Latin characters?
This first local release uses the PDF standard Helvetica font so the output does not need a remote font download. Unsupported glyphs are blocked instead of producing a blank mark.
Ready after the local engine loads
Keep the tab open while processing larger PDFs. Cancellation is checked between pages and no partial output is published.
Continue editing pages
Correct orientation or page geometry before applying a consistent visible watermark.
Continue your workflow
Related tools
These available PdfEditorOnlineFree tools are connected to add watermark by the tool catalog.