Stamp PDF — Add a Stamp to Any PDF
Add a CONFIDENTIAL, DRAFT, or custom text stamp to every page of your PDF. Customize font, opacity, and position. Free, private, 100% browser-based.
Add a text stamp to your PDF pages for branding, confidentiality notices, or draft markings. Position the watermark text anywhere on the page with customizable font size and opacity — all processed locally in your browser.
Drop a PDF to add watermark
PDF files only
How It Works
Upload a PDF, type your watermark text (CONFIDENTIAL, DRAFT, DO NOT COPY, or any custom text), and configure the appearance: opacity, font size, rotation angle, and position. The tool loads your PDF using pdf-lib.js, then draws the watermark text on every page.
Processing is 100% local — your PDF is never uploaded to any server. The watermark is embedded directly into the PDF page streams, so it appears consistently in all viewers and when printed. The watermark layer sits behind existing content for readability.
Features
- ✓Custom text watermarks — CONFIDENTIAL, DRAFT, DO NOT COPY, or any text you enter
- ✓Adjustable opacity from 5% (subtle) to 100% (opaque)
- ✓Font size control from 12pt to 120pt for any document size
- ✓Rotation angle from -90° to 90° for diagonal, horizontal, or vertical placement
- ✓Position presets: center, corners, or custom placement
- ✓Applies to all pages automatically — no per-page setup needed
- ✓Preserves all original PDF content, fonts, and formatting
- ✓100% client-side — your documents stay private
How to Use This Tool
- Upload the PDF you want to watermark.
- Type your watermark text (e.g., CONFIDENTIAL, DRAFT, SAMPLE).
- Adjust opacity, font size, rotation, and position to match your needs.
- Click "Apply Watermark" and download the watermarked PDF. Every page is marked.
Perfect For
- →Law firms marking documents as CONFIDENTIAL or PRIVILEGED before sharing with opposing counsel
- →Publishers watermarking review copies with PROOF or NOT FOR DISTRIBUTION
- →Businesses marking internal documents as DRAFT during the review process
- →Real estate agents watermarking property photos and documents with their agency branding
- →Teachers marking answer keys and exam solutions to prevent unauthorized distribution
- →Corporate compliance teams marking sensitive documents for tracking and access control
Under the Hood
The watermark is drawn using pdf-lib's page.drawText() API, which adds the text as a new content stream operation on each page. The text is rendered with the specified font (Helvetica Bold), size, color (gray with alpha), rotation transform, and position coordinates. Since the watermark is drawn as part of the page's content stream, it is permanent and appears in all PDF viewers and when printed.