PDF Watermark — Add Text & Image Watermarks to PDF Free
Text · Logo · Diagonal · Tiled · Page Range · 5 PDFs Bulk · 100% Free
Add professional watermarks to your PDF files instantly — no software needed. Choose from text watermarks (CONFIDENTIAL, DRAFT, SAMPLE) or upload your own company logo. Control position, opacity, rotation and which pages to stamp. Works entirely in your browser — your PDFs never leave your device.
📤 Upload PDFs Max 5 files
Drop PDF files here
or click to browse · Max 5 PDFs · Any size
How to Add a Watermark to PDF Free
Upload your PDF files (up to 5 at once). Choose Text watermark — type your custom text like "CONFIDENTIAL" or "DRAFT" — or upload your company logo as an image watermark. Select position, opacity, rotation and mode (single, diagonal or tiled grid). Click Apply and download the watermarked PDF instantly — 100% free, no server upload, no login required.
How PDF Watermarking Works
This tool uses pdf-lib — a pure JavaScript PDF library — to embed watermarks directly into the PDF page content stream. Text watermarks use standard PDF fonts (Helvetica, Times Roman, Courier). Image watermarks are embedded as PDF image XObjects with configurable opacity. No re-encoding of existing content occurs.
Frequently Asked Questions
Can I add a CONFIDENTIAL watermark to my PDF for free?
Yes. Type "CONFIDENTIAL" in the text watermark field, choose diagonal mode for the classic look, set your preferred opacity (30–50% is standard), and click Apply. Your PDF is watermarked instantly — no signup, no cost.
Can I watermark only specific pages in my PDF?
Yes. Use the "Apply To Pages" option to watermark All Pages, First Page Only, Last Page Only, Odd Pages, Even Pages, or a custom Page Range (e.g., pages 2–5). This is useful for cover pages, confidential sections, or alternating headers.
What is the difference between foreground and background watermark?
Foreground watermarks appear on top of existing content — text and images will have the watermark overlaid. Background watermarks appear behind existing content, so your original text remains clearly readable on top of the watermark. Background mode is recommended for subtle branding.
Can I upload my company logo as a watermark?
Yes. Switch to "Image / Logo" watermark type and upload a PNG (with transparency) or JPG file. PNG with a transparent background gives the best result. You can control scale, opacity, rotation and position just like text watermarks.
Are my PDF files safe? Does anything get uploaded?
Completely safe. This tool runs 100% inside your browser using pdf-lib — a JavaScript library. Your PDF files are never uploaded to any server. CalcNation has zero access to your documents at any time.