Private browser PDF editing

Add a watermark to a PDF online.

Place customizable text on every page or a selected range, preview the result, and download a separate PDF created privately in your browser.

How to add a watermark to a PDF

1. Choose a PDF from your device.
2. Enter watermark text and adjust its color, size, opacity, rotation, and position.
3. Select every page or enter a custom page range.
4. Apply the watermark and download the separate PDF created in your browser.

Custom text watermark controls

Add labels such as Confidential, Draft, Sample, Copy, or a company name and check their placement in the live preview.

Private browser-local PDF watermarking

PDFMech previews, modifies, validates, and downloads the PDF locally without uploading the source document.

Watermark scope and document limits

A watermark is a visible label rather than access control, encryption, redaction, or copy prevention. Modifying a signed PDF invalidates its existing signatures.

Add a watermark to a PDF online FAQ

Does PDFMech upload my PDF?

No. Page previews, watermarking, validation, and download happen locally in your browser.

Can I watermark only certain pages?

Yes. Choose Custom range and enter pages such as 1, 3-5, 8.

Can I use a transparent watermark?

Yes. Adjust opacity from 5% to 100% and review the result in the live page preview.

Does a watermark protect confidential information?

No. A watermark is a visible label. Use password protection, secure redaction, and appropriate access controls for sensitive documents.