Free Online PDF Watermark — Add Text & Image Watermark to PDF in Browser

Overview: Stamp Text & Logo Watermarks onto PDF Pages Instantly

Add confidential text stamps, logos, and custom watermarks to your PDF documents locally without server uploads. All computations and data processing are executed 100% locally on your device using client-side WebAssembly, HTML5 Canvas, and modern Web APIs without uploading files to any external server.

Supported Formats

PDF Watermark Tool supports the following file formats:

  • .pdf — client-side processing support.

How to Use PDF Watermark Tool in Browser

  1. Upload PDF: Select or drop your PDF document into the secure local viewer.
  2. Configure Watermark: Choose text or image, adjust font size, color, rotation angle, opacity, and target pages.
  3. Download: Preview the rendered watermark simulation and download your watermarked PDF immediately.

Key Features & Privacy Protections

  • 100% Client-Side Privacy: Zero cloud upload. Your documents, photos, and files never leave your local browser sandbox.
  • Zero Installation: Runs instantly in Chrome, Safari, Firefox, Edge, Android, and iOS browsers.
  • Free Forever: No sign-up, no subscriptions, no ads, and no file size limits.

Frequently Asked Questions (FAQ)

Does this PDF watermark tool upload my files to any server?

No. All PDF operations run 100% locally on your machine using client-side pdf-lib. Your confidential documents never leave your browser.

Can I add both text stamps and image logos?

Yes, you can toggle between text watermarks (with custom fonts, opacity, colors, and angles) and image watermarks (uploading your PNG/JPG company logo).

Can I apply the watermark to specific pages only?

Yes, you can apply watermarks to all pages, the first page only, or specify custom page ranges such as '1, 3-5, 8'.

Will the watermarked PDF work on Adobe Acrobat and mobile readers?

Yes, the exported file is a standard ISO 32000 compliant PDF readable by any standard PDF software, mobile reader, or web browser.

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PDF Watermark Tool

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v1.0.0Free · pdf-libPDF Tools

Free Online PDF Watermark — Add Text & Image Watermark to PDF in Browser

Stamp Text & Logo Watermarks onto PDF Pages Instantly. Add confidential text stamps, logos, and custom watermarks to your PDF documents locally without server uploads.

What is Watermark and what does it do?

The PDF Watermark Tool is a professional client-side document protection utility that embeds custom text stamps, confidential notices, copyright disclaimers, or corporate brand logos directly onto PDF pages directly inside your web browser.

Engineered for high confidentiality, your sensitive contracts, reports, and invoices never leave your computer. With flexible controls for font size, opacity, rotation angle, text color, and target page ranges, you can batch watermark documents in seconds without server subscriptions or privacy risks.

  • Add custom text watermarks such as 'CONFIDENTIAL', 'DRAFT', 'SAMPLE', or custom company names.
  • Fine-tune visual appearance with granular controls for rotation angle (-90° to 90°), opacity (5% to 100%), font size, and color.
  • Target specific page ranges: all pages, first page only, last page only, or custom comma-separated page numbers.
  • Process multi-page PDF documents locally with instant high-resolution vector rendering.
  • 100% private offline PDF manipulation using WebAssembly and pdf-lib with zero server uploads.

How does Watermark work?

When a PDF is loaded, pdf-lib parses the document's binary structure into an in-memory document tree. The selected watermark configuration is mapped into an affine transformation matrix specifying exact rotation, scale, and alpha blending.

Vector glyphs and coordinate offsets are applied to the content streams of each matching page. The final document is serialized into a clean binary blob for instant, one-click download entirely within browser memory.

100% private: all processing happens locally in your browser using client-side WebAssembly, HTML5 Canvas, and modern Web APIs. Your files are never uploaded to any server.

Who needs Watermark?

Legal & Compliance Officers

Apply confidential or restricted distribution disclaimers to sensitive legal filings, NDAs, and audit reports.

Financial Analysts & Accountants

Stamp draft financial statements, investment memorandums, and quarterly projections before external reviews.

Educators & Content Creators

Protect proprietary course syllabi, research papers, and ebooks with copyright markings and author watermarks.

Freelancers & Agencies

Brand client deliverables and draft design proposals with sample watermarks prior to final project sign-off.

Supported file formats

PDF Watermark Tool processes the following file extensions and data formats directly in your browser:

.pdf

How to use Watermark — step by step

  1. 1

    Upload PDF

    Select or drop your PDF document into the secure local viewer.

  2. 2

    Configure Watermark

    Choose text or image, adjust font size, color, rotation angle, opacity, and target pages.

  3. 3

    Download

    Preview the rendered watermark simulation and download your watermarked PDF immediately.

Frequently asked questions

Does this PDF watermark tool upload my files to any server?

No. All PDF operations run 100% locally on your machine using client-side pdf-lib. Your confidential documents never leave your browser.

Can I add both text stamps and image logos?

Yes, you can toggle between text watermarks (with custom fonts, opacity, colors, and angles) and image watermarks (uploading your PNG/JPG company logo).

Can I apply the watermark to specific pages only?

Yes, you can apply watermarks to all pages, the first page only, or specify custom page ranges such as '1, 3-5, 8'.

Will the watermarked PDF work on Adobe Acrobat and mobile readers?

Yes, the exported file is a standard ISO 32000 compliant PDF readable by any standard PDF software, mobile reader, or web browser.

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