Free Add Watermark
Add text or image watermarks to PDFs — 100% free in your browser.
Free How to use Add Watermark
Every PDF tool on DigitalConverter.online runs entirely inside your web browser using modern JavaScript libraries such as pdf-lib and PDF.js. When you merge, split, compress, or convert a document, the bytes of your file are read into memory on your device and processed locally without being uploaded to our servers. That client-side architecture means sensitive contracts, tax forms, and personal records never leave your computer during the operation, which is a meaningful privacy advantage over traditional cloud converters. The only exceptions are Word-to-PDF and PDF-to-Word conversions, which require server-side processing because accurate DOCX layout preservation depends on specialized conversion engines that cannot run reliably in every browser.
What Add Watermark does and when to use it
Add Watermark overlays text or image stamps across PDF pages to mark drafts as confidential, brand client deliverables, or deter casual copying of preview materials. Publishers watermark galleys, agencies stamp proofs with client names, and legal teams label documents PRELIMINARY before final execution.
Watermarks communicate status without altering underlying content structure, so recipients can still search and select text unless restrictions are applied separately. A diagonal semi-transparent label clearly signals that a file is not final, reducing misunderstandings when multiple versions circulate.
How this tool works
The watermark tool draws text or embedded images onto each page using pdf-lib drawing primitives, with configurable opacity, rotation, font size, and positioning. Image watermarks are rasterized once and repeated per page; text watermarks use standard font embedding where available.
Rendering occurs locally, so unreleased creative work stays on your machine. Watermarks become part of the page content stream and flatten into the PDF rather than living as a removable annotation layer in most outputs.
Step-by-step instructions
Upload your PDF, choose text or image watermark, and enter the label or select a logo file. Adjust opacity, angle, and placement using the preview controls, then apply to all pages or a subset if supported. Download the stamped PDF and review a few pages at zoom to ensure readability of underlying text.
Tips and best practices
Keep watermark opacity low enough that body text remains readable; around 15–25 percent is a common starting point for DRAFT labels.
For logos, use PNG with transparency so backgrounds do not obscure content.
Learn more: Reduce PDF File Size for Email and Web Uploads
Add Watermark FAQ
Answers to common questions about Add Watermark.
Related Tools
More free pdf tools you might find useful.