Add Watermark

Stamp text or an image watermark onto every PDF page.

or drop PDF here

Runs in your browser — your file never leaves your device.

Stamp text like CONFIDENTIAL, DRAFT or a client name across every page of a PDF, privately, in your browser. Watermark PDF draws the text as real content on each page, so it appears in every viewer and survives printing. You choose the wording, the typeface and colour, the opacity, and whether the text runs diagonally across the page or horizontally. "Scale to fit" sizes it automatically per page, which is what keeps the mark readable on a mix of A4 and Letter pages. Nothing is uploaded.

How to use Add Watermark

Click "Select PDF file" and choose the document to mark.
Type your watermark text. "CONFIDENTIAL" is filled in already, but any short phrase works — a client name, a date, or "DRAFT — NOT FOR CIRCULATION".
Set the style if you want something other than the default grey, then adjust opacity. Around 20% keeps the page readable underneath; above about 40% the mark starts to fight with the text.
Leave "Scale to fit" ticked unless you want a fixed point size. Keep "Diagonal" ticked for the usual across-the-page look, or untick it for a straight horizontal band.
Click "Add Watermark" and download the marked copy.

Who it is for

Watermark PDF is for marking a document before it goes out: CONFIDENTIAL on a board pack, DRAFT on anything still under review, a client's name on a report so a leaked copy identifies its source, or a date on a quotation so an old one cannot be passed off as current. It is also used to put a visible notice on a sample without covering the content.

How it works

The text is drawn into each page as normal page content, so it prints, appears in every viewer, and cannot be switched off from a layers panel.
Scale-to-fit recalculates the size per page, which is what keeps the mark readable on a mix of A4 and Letter — a fixed point size that fits one looks tiny on the other.
Opacity is a percentage you set, with the default chosen so the text underneath stays readable.

What it cannot do

Text only — no image or logo. A logo has to be placed with Edit PDF or Annotate PDF.
The mark is not tamper-proof. Someone with a PDF library can remove or cover it; the mark is a deterrent, not protection.
A darker or larger mark fights with the page. On a busy document, lower the opacity rather than enlarging the text.
It applies to the whole document; there is no page-range option.

Frequently asked questions

Is the watermark part of the page or a separate layer?

It is drawn into each page as normal page content, not as a removable annotation or a separate overlay layer. That means it prints, it shows in every PDF viewer, and it cannot be switched off from a layers panel. It is still technically removable by someone who edits the file with a PDF library — no visible mark is truly tamper-proof — but it is not a checkbox anyone can untick.

Why does my watermark look different on pages of different sizes?

Because "Scale to fit" recalculates the size for each page, sizing the text to roughly four-fifths of the width available so it reads the same on every sheet. That is deliberate: a fixed 60pt mark that fits a Letter page looks tiny on an A3 drawing. If you want the identical point size everywhere instead, untick the option and set the size yourself.

Can I add an image or a logo as a watermark?

Not with this tool — it sets text only. A logo would need to be placed with Edit PDF or Annotate PDF, both of which let you position an image on the page.

Will the watermark be behind or in front of the text?

In front, at the opacity you choose. At the default 20% the underlying text stays readable while the mark is clearly visible. If your pages are already busy, either drop the opacity or pick a lighter colour rather than making the mark larger.

Is my file uploaded?

No. The PDF is opened, marked and saved in your browser with pdf-lib, so a confidential document never leaves your device. The original file is untouched; you download a new copy.