How to use Watermark PDF
- Select or drop your PDF.
- Choose text or image, then set color, opacity, size, angle and position (center or tiled).
- Optionally limit it to certain pages, then click “Add watermark” and download.
Protect and label your documents
A visible watermark discourages copying and makes the status of a document obvious: mark drafts, add “Copy for XYZ only” to an ID you send to a landlord, or brand a portfolio with your logo. Tiled mode repeats the mark across the whole page, which makes it much harder to crop out.
Any language, any script
Text watermarks are drawn with your device’s fonts, so Chinese, Japanese, Korean, Arabic, Cyrillic and emoji all work. The watermark is added as a semi-transparent image on top of the page; the original content underneath is unchanged.
🔒 Your files never leave your device
bopdf processes your documents locally with JavaScript (pdf-lib and Mozilla pdf.js) inside your browser tab. Your PDF is never uploaded, stored or seen by us — you can even disconnect from the internet after the page loads and the tool keeps working. When you close the tab, everything is gone.
Frequently asked questions
Can the watermark be removed?
A determined person with editing software can remove most visible watermarks. Tiled watermarks are much harder to remove than a single stamp.
Can I use my logo?
Yes — choose “Image” and select a PNG (transparent background works best) or JPG.
Can I watermark only some pages?
Yes. Type a range like 2-5 in the Pages field, or leave the default to mark all pages.
Is my file uploaded?
No. The watermark is applied locally in your browser.
Are my files uploaded to a server?
No. Everything happens in your browser on your own device. Files are never sent over the internet, which makes bopdf suitable for confidential documents.
Is there a file size limit?
There is no fixed limit, but very large files (hundreds of MB) depend on your device memory. On phones, files up to about 100 MB usually work well.