Aivoryx PDF Tools

Add a Watermark to a PDF — Free & Online

Marking a document as a draft, confidential, or a sample before sharing it usually means opening a PDF editor just for one stamp. This tool adds a diagonal text watermark across every page entirely in your browser — type your text, adjust how visible it is, and drop in as many files as you need. Each one downloads the moment it's watermarked, with nothing ever uploaded to a server.

Frequently asked questions

Can I use my own watermark text?
Yes — type anything you like (e.g. "DRAFT", "SAMPLE", a company name). It defaults to "CONFIDENTIAL" if left blank.
Can I control how visible the watermark is?
Yes, with the opacity slider — lower it for a subtle stamp that doesn't interfere with reading the page, or raise it for a bold, unmissable mark.
Does the watermark get added to every page?
Yes — every page in the document gets the same diagonal watermark.
Can I watermark more than one file at a time?
Yes — drop multiple PDFs and each one is watermarked independently with the same text and opacity, with its own download button.
Are my files uploaded anywhere?
No. Watermarking happens entirely in your browser in a background thread; your files never leave your device.