PDF tool
Watermark PDF
Add a diagonal text watermark to every PDF page.
Watermark PDF workspace
Workspace
Watermark PDF
Drop a PDF here
or · PDF files only
pdf-lib reads and writes the document in your browser. Large documents may take a moment; encrypted PDFs may not open.
Your PDF result will appear here.
No page is uploaded to create it.
The guide
By the utils.sbs team · Reviewed November 2026 · How we build and review tools
Quick answer
Watermark PDF is a free browser-based pdf tool. Add a diagonal text watermark to every PDF page. It runs with pdf-lib locally, requires no account and does not upload your files. Open the page, add your input, adjust any options and download the result.
What is Watermark PDF?
Watermark PDF is a free browser-based pdf tool from utils.sbs. Add a diagonal text watermark to every PDF page. It is built for quick, focused jobs: open the page, add your input, adjust the options and take the result with you. No account, install or server upload is required.
At a glance
| Category | |
|---|---|
| Input | PDF, or images for image-to-PDF operations |
| Output | A PDF, extracted text or archive, depending on the operation |
| Engine | pdf-lib |
| Processing | In your browser |
| Price | Free |
| Account | Not required |
How Watermark PDF works
PDF pages are parsed and written with pdf-lib in the browser. The document stays on your device from upload to download.
How to use Watermark PDF
- 1Open Watermark PDF and add your input.
- 2Adjust the options: watermark text, opacity, font size, angle.
- 3Run the tool, check the preview or result, and download the output.
When to use Watermark PDF
- Organise, split or combine pages before sending a document.
- Extract text or convert a PDF for another workflow.
- Add a signature, watermark or page numbers to a document.
Inputs and options
- Watermark text
- Set this value before running the tool.
- Opacity
- Set this value before running the tool.
- Font size
- Enter a numeric value.
- Angle
- Enter a numeric value.
Limitations
Scanned PDFs may not expose selectable text, and very large documents can be slow on low-memory devices.
Privacy and accuracy
Watermark PDF processes its input in the browser whenever the platform API allows it. Files and values are not uploaded to a server for processing, and the tool does not require an account. For calculations, use the result as a reference and verify important decisions against the source formula or a qualified professional. Read our methodology.
FAQ
Watermark PDF questions
What can I do with Watermark PDF?
Add a diagonal text watermark to every PDF page. Watermark PDF is part of the PDF shelf on utils.sbs and is designed for quick, one-off tasks.
Is Watermark PDF free to use?
Yes. Watermark PDF is free, requires no account, and has no per-file or per-use charge.
Are my files uploaded when I use Watermark PDF?
No. Watermark PDF is designed to process your input locally in the browser. Files are not uploaded to a server for processing.
What formats does Watermark PDF support?
It works with PDF input and produces a downloadable PDF or extracted text, depending on the operation.
Can I use Watermark PDF on my phone?
Yes. Watermark PDF is responsive and works in modern mobile browsers. Very large files may be limited by the device's available memory.
Keep going
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- Merge PDFCombine several PDFs into one document, in your order.
- Split PDFSplit a PDF at page ranges and download a ZIP of results.
- Extract PDF PagesKeep only the pages you specify in a new PDF.
- Delete PDF PagesRemove unwanted pages without re-uploading anywhere.
- Rotate PDFRotate every page or selected pages by 90/180/270°.
- Reorder PDF PagesArrange pages in any order using a simple page list.