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Add Watermark to PDF — Text Stamp & Overlay

Watermark PDFs with text presets or custom text — adjust font, opacity, rotation and colour. Processing runs locally in your browser; limits depend on the document.

  • Add text watermarks with custom font, size, color, opacity
  • Rotate and position anywhere on the page
  • Preview before applying — watermark renders via pdf-lib locally

Watermarks signal intent visually — DRAFT, CONFIDENTIAL or custom text — so a review copy is not mistaken for a final deliverable. OpenPDF lets you adjust font, opacity, rotation and colour and renders the result locally with pdf-lib. The operation has document limits; review the exported PDF before sharing.

How it works

  1. Upload the PDF. Drop the PDF you want to watermark onto OpenPDF.
  2. Enter the watermark text. Type the text or choose an image. Adjust font, size, color, rotation, and opacity.
  3. Pick a position. Place the watermark in the center, corners, or tile it across every page.
  4. Export the PDF. OpenPDF stamps the watermark onto every page in your browser and hands you the watermarked PDF.

Common use cases

  • Stamping "DRAFT" across every page of a proposal before internal review.
  • Adding a "CONFIDENTIAL" mark to PDFs shared under NDA.
  • Branding client deliverables with a semi-transparent company logo on each page.
  • Marking exported samples with a visible source URL before sharing publicly.

Frequently asked questions

Can watermarks be removed by a determined user?

A flattened watermark is baked into the pixels of the page and is hard to remove cleanly, but modern PDF tools can sometimes undo a text overlay. For strong protection, combine with a large opacity and place over the main content.

Can I use an image watermark?

Yes, in addition to text. Upload a logo PNG (ideally with a transparent background) and position it with the same controls as text watermarks.

Can I watermark only specific pages?

Yes. Choose a page range — all pages, a custom range, or specific individual pages.

Is the watermark uploaded?

Watermark rendering happens on your PDF locally in the browser; document limits still depend on the operation and device.

Why OpenPDF

OpenPDF is an independent project where PDF document processing runs in the browser using WebAssembly and modern JavaScript APIs. The toolkit includes merge, split, sign, organize, annotate, compress, watermark, page numbers, add image and fill forms. Practical limits depend on the operation, document and device. The page source and privacy policy describe consent controls, analytics, advertising and optional services before you use the tool with sensitive documents.

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