Watermark PDF adds a semi-transparent text stamp to every page of a document. Watermarks discourage unauthorised copying, mark a document as a draft or sample, and show who it belongs to, which helps when you share contracts, design proofs or exam papers.
Type any text, pick a colour, size, opacity and angle, and the watermark is centred on each page. The original content stays readable underneath, and the file never leaves your computer.
How to use the Watermark PDF tool
- Select the PDF to watermark.
- Type your watermark text, for example DRAFT or your company name.
- Adjust the colour, font size, opacity and angle.
- Click Add watermark and download the result.
Features
- Custom text, colour, size and transparency.
- Diagonal, horizontal or vertical placement.
- Applied automatically to every page.
- Content underneath stays readable and selectable.
- Private and free, with no sign-up.
Tips for best results
An opacity of 15–30% keeps the document readable while making the mark obvious. For long text, lower the font size so the watermark fits across the page. A watermark discourages misuse but it isn't tamper-proof, so for sensitive documents, share them only with people you trust.
Compatibility and limits
The Watermark PDF tool works in current versions of Chrome, Edge, Firefox, Safari, Opera and Samsung Internet, on desktop and mobile. Processing speed depends on your device: a typical document finishes in a few seconds, while files with hundreds of pages or very large scanned images may take longer on older phones. Encrypted (password-protected) PDFs must be unlocked before they can be processed. Your original file is never changed, because the result is always saved as a new download.
Privacy: your files never leave your device
Your PDF is opened and processed by JavaScript running in your own browser, using open-source libraries we host ourselves. The document is never uploaded to our server or anyone else's. Once the page has loaded, the tool even works without an internet connection. Close the tab and the file is gone from memory.
Frequently asked questions
Can I add an image or logo as a watermark?
This tool adds text watermarks. Writing your brand name in a matching colour works well as a simple logo mark.
Can the watermark be removed?
A text watermark can be removed by someone with PDF editing software. It deters casual copying but is not strong protection.
Will it make my text unreadable?
Not at low opacity. 20–30% is a good balance.
Is my document uploaded?
No. The watermark is applied in your browser.
Does it support non-English watermark text?
The standard PDF font supports Latin characters. Other characters are replaced with question marks.