FastHan / PDF Tools / Watermark PDF
WATERMARK PDF
Watermark PDF
Add a text watermark to every page of a PDF — DRAFT, CONFIDENTIAL, or your own words.
100% private — processed in your browser
Your files are processed locally in your browser with JavaScript. They are never uploaded to a server. You can verify this yourself: open your browser DevTools, go to the Network tab, and watch — no file data leaves your device.
How to add a watermark to a PDF
A watermark marks a document as yours, or as a draft, or as confidential — without changing the document itself. It is the standard way to share a contract for review, a report before it is final, or a design proof that should not be mistaken for the finished version. This tool adds a text watermark diagonally across every page of your PDF, in a colour and opacity you choose.
Drop a PDF and type the watermark text. Common choices are DRAFT, CONFIDENTIAL, SAMPLE, or your name or company. Pick a colour (red is the classic stamp colour, grey is subtler) and an opacity — lighter keeps the page fully readable, stronger makes the mark impossible to miss. You can also add a date line under the text. Press Add Watermark and download the finished PDF. The watermark is drawn onto each page, so it travels with the file and cannot be removed by turning a viewer setting off.
Everything runs in your browser, so contracts and drafts never leave your device. The watermark does not change the underlying text or images; it is an overlay, which means the document stays searchable and printable exactly as before. If you need to mark a document as paid, the Merge PDF tool does that too — tick "Add watermark" there and it combines merging with a stamp in one step.
A practical tip: for a draft that will be reviewed on screen, a stronger opacity is fine; for a document that will be printed and read closely, choose a lighter opacity so the text underneath stays comfortable to read.
How to use this tool
- 1Drop a PDF file onto the page.
- 2Type the watermark text and pick a colour and opacity.
- 3Press Add Watermark and download the stamped PDF.
Frequently asked questions
What text should I use as a watermark?
Anything: DRAFT, CONFIDENTIAL, SAMPLE, your name, or a company name. You can also add a date line under the main text.
Will the watermark hide the document text?
No. The watermark is semi-transparent and drawn diagonally, so the text underneath stays readable. Choose a lighter opacity for documents that will be read closely.
Can I watermark several PDFs at once?
Yes. Drop several PDFs and they are merged first, then watermarked as one document. For invoices, the dedicated merge-and-stamp page does the same thing with a PAID stamp.
Are my files uploaded anywhere?
No. Watermarking happens entirely in your browser. Your documents never leave your device.