Create a text or logo watermark
Enter supported Latin text or upload a static PNG or JPEG logo. Adjust color, opacity, scale, and rotation while using the selected-page preview to check how the watermark will sit over the document.
Add a Watermark to PDF Online
Add a text or image watermark to PDF pages online for free. Control opacity, scale, rotation, tiling, position, and page range in your browser.
Processing stays in your browser.
Place a watermark
Add text or a PNG/JPEG image to selected pages without rasterizing the original PDF.
PDF preview
Preview is approximate. Export keeps document pages as PDF vectors.
Changing this PDF can invalidate cryptographic signatures.
Applying watermark0%
Cancellation runs between pages. Browser PDF loading or final saving may finish its current native phase first.
Add a PDF to begin.
Practical guide
Add a text or image watermark to a PDF
Create a visible document watermark for review copies, ownership labels, drafts, or internal distribution. RealScaner stamps the selected PDF pages locally and keeps the original page content as PDF data instead of flattening it into screenshots.
Choose placement, tiling, and page range
Place one watermark in any of nine page positions or repeat it as a tiled pattern. Exact page ranges let you watermark every page, selected sections, or individual pages without altering excluded pages.
Preserve the original PDF page structure
The watermark is added with PDF drawing operations, so page dimensions, rotations, and vector content remain intact. Any modification can invalidate an existing cryptographic signature, and the tool displays that warning before download.
Common questions
Practical answers about privacy, formats, and output quality.
Does RealScaner upload my PDF or watermark?
No. PDF validation, preview, image embedding, text stamping, and download preparation all run in your browser.
Which watermark images are supported?
Use a static PNG or JPEG. PNG alpha transparency is preserved. Empty, unreadable, deceptive, and other image types are rejected.
Which text characters can I use?
This version uses the PDF WinAnsi character set for embedded Helvetica. Common Latin letters and punctuation work. Unsupported characters are reported before processing.
Can I watermark only selected pages?
Yes. Enter an exact list such as 1, 3-5. Invalid syntax, overlapping selections, and pages outside the document are rejected.
Will watermarking flatten the original PDF pages?
No. Text and images are added as PDF drawing operations. Existing page dimensions, rotations, and vector content are preserved.
Can watermarking invalidate a digital signature?
Yes. Any PDF modification can invalidate a cryptographic signature. RealScaner warns when common signature markers are detected.
Is the selected-page preview exact?
It is a close browser preview of placement, scale, rotation, and opacity. Font metrics can vary slightly in the exported PDF.