Add Watermark to PDF
Add a text watermark with opacity control. Document processing happens locally in your browser.
A visible watermark is not a security control. It does not prevent copying, editing or removal, and it does not prove protection.
Drop your PDF here
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Place a text label across each page
Text and opacity are the controls
Enter text supported by the built-in Helvetica Bold font and choose opacity from 10% to 80% in 5% steps. The default is CONFIDENTIAL at 30%. This is a text-only watermark; there is no image-logo upload, font picker, color picker or manual position/angle control.
PDFcraft draws one gray label per page at a displayed 45-degree angle. Placement accounts for existing rotation and the crop/media intersection. Font size starts from the visible page size and is reduced when necessary to fit longer text; it is not a tiled/repeated pattern.
Fit and readability
The input has no fixed character-count limit, but the font cannot encode every character and very long text may become tiny. Invalid visible page geometry or unsupported characters can stop the operation. Try a short label and check it on every distinct page size.
Node geometry tests checked positioning on cropped and rotated pages; extraction checks observed the added text. Those checks do not prove universal visual fidelity. A label may discourage casual reuse, but someone able to edit the PDF may remove it.
A new copy with visible additions
The overlay is drawn into page content rather than used as encryption or access control. It does not remove existing text. The browser loads and rewrites the PDF locally; the watermark handler does not send it to a processing service. Website loading can still make network requests.