How the PDF Watermark Tool Works
DocDox PDF Watermark embeds customizable text or image watermarks into every page of a PDF document in your browser, using pdf-lib and a live canvas preview. Watermarks are burned directly into the PDF page content — they become part of the document and cannot be removed by simply deleting a layer.
Text watermarks support full customization: choose your watermark text (such as "CONFIDENTIAL," "DRAFT," "SAMPLE," or your company name), then configure the font size, opacity, rotation angle, and color. A canvas-rendered preview updates in real time as you adjust settings, showing you exactly how the watermark will appear before exporting. Image watermarks let you upload a logo PNG and control its size, opacity, and position across each page.
Everything runs locally — no file upload, no server processing. Even large PDFs with many pages are processed entirely on your device, with no file size restrictions and no cloud dependencies.
Can the watermark be removed?
Watermarks added by this tool are burned into the PDF content, not added as a layer. Removing them requires advanced PDF editing tools and is not trivial.
Can I watermark just specific pages?
Currently the tool applies the watermark to all pages. Per-page watermarking is on the roadmap.
Does watermarking affect the text content or searchability of the PDF?
No. The watermark is added as a visual element. Existing text remains selectable and searchable.