Add PDF Watermark
Add a text watermark with custom font size, opacity, rotation and color
About this tool
Add PDF Watermark stamps a configurable text watermark over every page of a PDF. You can set the watermark text (e.g. CONFIDENTIAL, DRAFT, sample), font size (10-120 pt), opacity (5-100%), rotation angle (-90° to +90°) and RGB color. The watermark is rendered diagonally across the page using pdf-lib's StandardFonts. Common scenarios include marking confidential drafts before sharing, watermarking client samples, labeling internal-only documents, and adding compliance markings. All processing happens locally in your browser; the file and watermark text never leave your device. Maximum file size is 50 MB.
Frequently Asked Questions
Can I watermark only certain pages?
Not in this version — the watermark applies to every page. For per-range watermarking, split the PDF first, watermark each part, then merge.
Why does my Chinese watermark look like boxes?
The tool uses pdf-lib's StandardFonts which only support ASCII/Latin characters. Use English text for now. CJK font embedding is on the roadmap.
Is the watermark removable from the output PDF?
It is rendered as page content, not as a removable annotation. It cannot be easily removed, which is the point of a watermark.
Is my PDF uploaded to any server?
No. Everything is processed locally in your browser using pdf-lib. The PDF and watermark text never leave your device.
What is the file size limit?
50 MB. The limit is set client-side and depends on browser memory.
Why is the watermark rotated diagonally by default?
Diagonal watermarks are harder to crop out and are the de facto standard for confidential/draft marking. You can set rotation to 0° for horizontal text.
When is this most useful?
Marking confidential drafts, branding client samples, labeling internal-only docs, applying compliance text before distribution.
Keep browsing