How does rotation interact with position?

Position targets the VISUAL CENTRE of the (possibly rotated) text. For example, with 45° rotation and “middle-center”, the text is rotated 45° around the page centre. With “top-left” and 0°, the text sits horizontally in the top-left corner with the configured margin.

Is my PDF uploaded somewhere?

No. The PDF is read into browser memory only and edited with the pdf-lib library. The watermark is drawn locally; the file never leaves your device.

Can I use a transparent PNG or logo instead of text?

This tool stamps text only. For an image watermark, embed the image with doc.embedPng / doc.embedJpg and use page.drawImage in custom code, or use the Watermark Image tool for a rasterised overlay.

Why does my watermark look slightly off-centre?

The position is computed using the text's bounding box (width × height) which assumes Helvetica Bold's standard metrics. Kerning and glyph-specific overshoots can cause a few points of visual drift. Use a larger margin or pick middle-center for the most reliable result.

PDF Tools

Watermark PDF

Stamp a text watermark across every page of a PDF — entirely in your browser. Choose the text, font size, colour, opacity, rotation angle and one of nine positions, then download the watermarked result. Perfect for “CONFIDENTIAL”, “DRAFT” or branding overlays. Your file never leaves your device.

Your file is processed locally in your browser. It is not uploaded to Dueneo.

Loading Watermark PDF…

How to use

1
Upload a PDF
Drag and drop a PDF onto the dropzone. The page count is read in the background so you can confirm the scope before watermarking.
2
Configure the watermark
Type the watermark text, pick a font size, colour (hex picker or presets), opacity (5–100%), rotation angle (0–359°), margin and one of nine positions on the page.
3
Preview
A live mini-preview shows the text in your chosen colour, opacity and rotation. The preview is approximate — the final position is computed per page using each page's actual dimensions.
4
Apply and download
Click Apply watermark — pdf-lib draws the text on every page locally using drawText with embedded Helvetica Bold. Download the result; your file never leaves your device.

Common use cases

Stamp “CONFIDENTIAL” diagonally across every page of a contract before sharing externally.
Brand every page of a white paper with your company name in the top-right corner.
Mark a draft proposal with “DRAFT v2 — DO NOT DISTRIBUTE” at 30° across the middle.
Add a subtle copyright notice in the bottom-centre of every page of an e-book PDF.

Limitations

The watermark uses Helvetica Bold only — embedding a custom TTF/OTF font is not exposed in the UI. To use a custom font, embed the bytes via doc.embedFont in custom code.
Each character's glyphs are drawn in the chosen colour and opacity; this is a flat text overlay, not a transparent PNG stamp. Transparent backgrounds behind the text are preserved.
Encrypted or password-protected PDFs cannot be watermarked — remove the password first.
The same text, size, colour, opacity and angle are applied to every page. To vary the watermark per page, split the PDF first, watermark each part separately, then merge.
Very large PDFs (>100 MB) may take several seconds to process and use significant memory.

Frequently asked questions

Related tools

View all

PDF Merge

Combine multiple PDF files into one document.

pdf

Open

Add Page Numbers to PDF

Insert page numbers into a PDF document.

pdf

Open

Image to PDF

Convert one or more images into a single PDF document.

pdf

Open

Watermark Image

Add a text watermark to images with custom position and opacity.

image

Open

Loading Watermark PDF…

Watermark PDF

How to use

Upload a PDF

Drag and drop a PDF onto the dropzone. The page count is read in the background so you can confirm the scope before watermarking.

Configure the watermark

Type the watermark text, pick a font size, colour (hex picker or presets), opacity (5–100%), rotation angle (0–359°), margin and one of nine positions on the page.

Preview

A live mini-preview shows the text in your chosen colour, opacity and rotation. The preview is approximate — the final position is computed per page using each page's actual dimensions.

Apply and download

Click Apply watermark — pdf-lib draws the text on every page locally using drawText with embedded Helvetica Bold. Download the result; your file never leaves your device.

Common use cases

Stamp “CONFIDENTIAL” diagonally across every page of a contract before sharing externally.

Brand every page of a white paper with your company name in the top-right corner.

Mark a draft proposal with “DRAFT v2 — DO NOT DISTRIBUTE” at 30° across the middle.

Add a subtle copyright notice in the bottom-centre of every page of an e-book PDF.

Limitations

The watermark uses Helvetica Bold only — embedding a custom TTF/OTF font is not exposed in the UI. To use a custom font, embed the bytes via doc.embedFont in custom code.
Each character's glyphs are drawn in the chosen colour and opacity; this is a flat text overlay, not a transparent PNG stamp. Transparent backgrounds behind the text are preserved.
Encrypted or password-protected PDFs cannot be watermarked — remove the password first.
The same text, size, colour, opacity and angle are applied to every page. To vary the watermark per page, split the PDF first, watermark each part separately, then merge.
Very large PDFs (>100 MB) may take several seconds to process and use significant memory.