Free online PDF tool
Add a text watermark to your PDF
Mark a PDF as confidential, draft, approved or internal before sharing it. Enter custom text and select an opacity to place a diagonal watermark across the document pages.
Use Watermark PDFHow it helps
A straightforward way to work with your document
Watermarks help communicate document status and discourage casual reuse. They are not a substitute for encryption or access controls when a file contains highly sensitive information.
The watermark is added in your browser. The source PDF is not uploaded for the transformation and you do not need to register.
Three simple steps
How to use Watermark PDF
- 1
Choose a PDF.
- 2
Enter the watermark text and opacity.
- 3
Download the marked document.
Professional use cases
When to use this tool
This workflow is useful for legal teams assembling exhibits, finance staff preparing statements or tax records, healthcare offices organizing administrative documents, and anyone handling files that should not be copied to an unnecessary conversion server.
PdfWiseAI creates a separate result and leaves the source unchanged. Review page order, image quality, visible content and the output filename before sharing the generated file.
Privacy verification checklist
Check the workflow before using sensitive documents
- Use a harmless sample file first and confirm the expected output.
- Prefer local transformations when no AI analysis is needed.
- Follow your organization’s security, legal and records policies.
- Keep originals until the generated file has been reviewed.
Local processing reduces document transfer, but it is not a certification of compliance with HIPAA, attorney-client duties or another regulatory framework.
Frequently asked questions
Watermark PDF FAQ
Can I use custom text?
Yes. Enter any short label appropriate for the document.
Can I adjust transparency?
Yes. Several opacity levels are available.
Is watermarking done locally?
Yes. The browser processes the PDF.
Can I use a logo or image as a watermark?
The text watermark tool accepts text only. For image-based watermarks, use the overlay tool to layer a transparent PNG or another PDF as the watermark.
Will a watermark prevent copying?
No. A watermark is a visible marker; it does not block copy, print, or screenshot. For stronger protection, combine watermarking with PDF encryption.
Can I change the watermark opacity?
Yes. Opacity can be set from 5 to 80 percent. The watermark text is rendered as a centered diagonal overlay in gray on every page, with the text you provide.
Does watermarking increase file size?
Only minimally. The watermark is added as a small vector text layer on each page, so the resulting PDF stays close to the original file size.