Watermark PDFFree Online PDF Tool

The Watermark PDF tool lets you add custom text watermarks to PDF files directly in your browser with complete control over appearance. You can customize the watermark text (e.g., 'CONFIDENTIAL', 'DRAFT', 'SAMPLE'), adjust font size from 12 to 120 pixels, control opacity from 5% to 100%, set rotation angle from -90 to 90 degrees, choose position (center, corners, or sides), and select color (gray, red, blue, green, black). All processing happens entirely in your browser—your PDF never uploads to any server.

Upload a PDF file by clicking the upload area or dragging and dropping your file. The tool reads the PDF into your browser's memory and displays the file name and page count. In the settings panel on the right, enter your watermark text in the text field. Adjust the font size slider (12-120px), opacity slider (5-100%), and rotation slider (-90 to 90 degrees) to control the watermark's appearance. Select your preferred position from the dropdown (center, top-left, top-right, bottom-left, or bottom-right). Choose a color that contrasts with your document content. See a live preview updating as you adjust settings. Once satisfied, click 'Add Watermark & Download'. The tool uses pdf-lib to process the PDF in your browser, adding your watermark text to every single page with your specified styling, then automatically downloads the watermarked PDF.

Unlike server-based PDF watermarking tools that require uploading your sensitive documents to unknown servers, this watermarker is completely private and secure—your PDF never leaves your device and never touches any external server. It's ideal for marking confidential documents before distribution, adding copyright notices to creative work, branding PDFs with your company name before sharing with clients, creating sample or preview versions, or protecting intellectual property. The tool is completely free, works instantly, and produces professional results without subscriptions or watermark limitations.