How to add a watermark to a PDF
A watermark answers a question the reader would otherwise have to ask: is this the final version, is this the original, am I allowed to pass this on. It is a label, not a lock, and the trouble starts when people expect it to be the second.
Add the PDF, type the text, choose the size, the colour and the opacity, and download. The watermark is drawn across every page in your browser, and nothing is uploaded.
Add a watermark freeStep by step
- Add your PDF
Drop the file on the tool. It is read and rewritten on your device, which matters because the documents people watermark are rarely the trivial ones.
- Write the text
Short and unambiguous: DRAFT, COPY, CONFIDENTIAL, a date, a recipient's name. A watermark nobody can read at a glance is decoration.
- Set size, colour and opacity
Between 15 and 25 % opacity marks the page clearly and leaves the text underneath perfectly readable. Grey is safer than a colour that will be printed as a black smear.
- Download the marked PDF
Every page carries the watermark. Keep the unmarked original — you will want it when the draft becomes the final version.
What a watermark actually does
It tells the reader how to treat the document. A page stamped DRAFT does not get quoted as final; a page stamped with the name of the person it was sent to does not get forwarded quite so casually.
That second use is the strongest one. Marking each copy with its recipient does not stop a leak, but it makes the source of one identifiable, and people behave differently when they know that.
It is not protection, and it can be removed
By default a watermark is drawn on top of the page as ordinary PDF content, which means somebody determined can strip it out with the right tool. Treat it as a label, not a security measure.
To make it permanent, flatten the document to images — converting to JPG and back, or compressing with the image option — which turns the page and its watermark into one picture. You lose selectable text in exchange, which is a real cost.
Choose an opacity that survives printing
On screen, a watermark at 10 % looks elegant. Printed on a grey office laser, it disappears entirely — and printed copies are exactly the ones that circulate without their context.
Fifteen to twenty-five per cent is the range that reads on paper and on screen without fighting the text. Print one page before committing to a setting for a document that matters.
Frequently asked questions
Can the watermark be removed afterwards?
By default yes, by someone determined: it sits on top of the page as normal content. Flattening the document to images makes it permanent, at the cost of selectable text.
Which opacity should I use?
Around 15 to 25 %. That marks the document clearly, stays visible when printed, and keeps the text underneath perfectly readable.
Can I watermark only some pages?
Not from this tool, which marks the whole document. For a single page, open the editor and add the text there, rotated and faded as you like.