PDF Watermark Tool - Add Text or Logo Free

The add watermark to pdf tool is a secure, client-side web utility that allows you to embed text or image watermarks directly into each page of your documents. While adding a watermark to a PDF normally requires Adobe Acrobat Pro or a server-side tool that processes your file remotely, this tool uses the pdf-lib JavaScript library to compile all modifications locally on your device.

The tool supports both text watermarks (type any text, choose color, font size, opacity, rotation, and position) and image watermarks (upload a PNG or JPG logo). A live preview on page 1 updates instantly as you adjust settings, so you can see exactly how the watermark will look before generating the final file.

The watermark is applied to every page of the document with identical settings. The output is a new PDF file - your original is never modified. Font rendering, embedded images, vector graphics, and hyperlinks in the original document are preserved exactly.

Watermarks serve two distinct purposes: document status labeling and ownership marking. Common use cases:

• CONFIDENTIAL or DRAFT: Mark internal documents before sharing them with external parties to indicate they are not final or not for public distribution.
• SAMPLE: Add a diagonal "SAMPLE" watermark to preview versions of reports, proposals, or design documents to prevent unauthorized use before payment.
• Company logo: Brand every page of a client-facing document with your company logo at low opacity so the content remains readable but the document is clearly attributed.
• DO NOT COPY: Add a visible deterrent to sensitive documents like exam papers, proprietary research, or legal filings.
• Recipient-specific marking: Add a recipient's name or email as a watermark before sending to track the source of any unauthorized distribution.

1. 1

   Upload your PDF

   Drag and drop your file into the upload area or click "Select PDF". The tool loads the first page into the preview canvas using pdf.js.

2. 2

   Choose text or image watermark

   Select the "Text" tab to type custom text, or the "Image" tab to upload a PNG or JPG logo. PNG files with transparent backgrounds work best for logos.

3. 3

   Adjust settings and preview

   Use the sliders to set opacity (0-100%), size, and rotation (0-360°). Choose a position from the dropdown. The preview on page 1 updates instantly - what you see is what every page will look like.

4. 4

   Add watermark and download

   Click "Add Watermark to All Pages". pdf-lib processes the document on your device and generates a download link. The output filename is prefixed with "watermarked_" to distinguish it from the original.

Using the correct settings ensures your watermarked documents look clean and professional. Opacity between 20-40% works well for diagonal center watermarks - visible enough to be noticed but not so heavy that it obscures the document content. For corner watermarks (top-right or bottom-right), 60-80% opacity is more appropriate since they cover less of the page.

A 45-degree rotation is the standard for diagonal watermarks and is the default setting. For corner watermarks, 0 degrees (horizontal) is usually cleaner. For logo watermarks, 0 degrees with a low opacity (15-25%) in the center position creates a professional background branding effect. If you need to watermark specific sections of a larger file, you can first use our utility to split PDF documents, apply the watermark to the target sheets, and then recombine them with the merge PDF files tool.