How to add a watermark to a PDF
Stamp DRAFT or CONFIDENTIAL across every page, control how it looks, and see why a watermark is not security.
A watermark says something about a document on the document itself: that it is a draft, that it is confidential, that it came from you and you would rather it did not circulate further. It is the cheapest form of provenance there is, and it works for one reason — everyone who opens the file sees it without being told where to look.
Add a watermark to a PDF
Upload the PDF
Drop in the document you want to stamp. Once its page count has been read, the controls and a live preview appear.
Type your text
The box starts at CONFIDENTIAL. Replace it with DRAFT, a company name, a case number, or whatever the document needs.
Set the look
Choose a size, an opacity, one of four colours, and one of six positions. The preview updates as you go.
Adjust the angle if you want one
Picking Diagonal sets the text to 45°. Any other position sets it flat at 0°. You can then type any angle you like over that.
Add watermark
Click Add watermark. The stamp is drawn onto every page on your own device and the file downloads.
What you can actually change
The defaults are chosen to be legible without burying the document underneath: CONFIDENTIAL, 48pt, grey, 35% opacity, running diagonally across the middle of the page at 45°. For most jobs that is the whole configuration, and the reason the preview exists is so you can disagree with it in about four seconds.
- The font size control offers 8 to 200. 48 is the default, and anything above roughly 120 will run off the edge of a portrait page on a long word.
- Opacity runs from 5% to 100%. Past about 60% you start fighting the text underneath rather than marking it.
- Four colours: grey, red, blue and black. There is no custom colour picker.
- Six positions: diagonal, centre, and the four corners.
- Rotation is a separate number, offered from 0 to 359. Choosing a position sets a sensible angle for you, but it never locks it — a corner stamp turned 30° is entirely possible.
The watermark is text, and only text
There is no image watermark here. You cannot stamp a logo, a scanned seal or a PNG onto the pages — the tool draws a line of text with a built-in font and nothing else. It is worth saying plainly, because "text or image watermark" is the kind of thing tools list without meaning it. If you need a graphic on every page, this is not the tool, and no amount of clicking will make it one.
Cyrillic, Chinese and emoji come out as question marks
This is the part worth knowing before you type. The stamp is drawn with a built-in Helvetica, and built-in PDF fonts can only encode WinAnsi — printable ASCII, the Latin-1 accented characters, and the Windows typographic row with the euro sign, smart quotes, dashes and the trademark sign. Anything outside that set has no glyph to draw, so each character is replaced with a literal question mark. Type СЕКРЕТНО and the finished PDF says ????????. Type 機密 and it says ??. A simple emoji becomes a single ? — composed ones like family emoji become several.
The good news is that you find this out before you commit, not afterwards. The workspace counts the unencodable characters and warns you right under the text box, and — the part that actually matters — the live preview shows the sanitized string rather than your input. So the preview says ???????? too. A preview that rendered СЕКРЕТНО in a browser font while the download said otherwise would be worse than no preview at all, because it would be actively lying to you.
The fix would be to embed a full Unicode font, and the reason we have not is honest rather than principled: a CJK font is megabytes, and every visitor to the page would download it whether or not they ever typed a Chinese character. If your watermark must be in a non-Latin script, use a desktop editor that can embed the font it needs.
Curly quotes stay curly
One thing you do not have to worry about: typographic punctuation. Curly quotes, en and em dashes, ellipses, bullets and the euro sign are all inside the font's encoding and are stamped exactly as you typed them. Paste “DRAFT” – v2 in and the page reads “DRAFT” – v2. This used to be quieter than it deserved — until July 2026 the tool straightened that punctuation into ASCII lookalikes without saying so, a limitation the font never actually had.
Every page, always
The stamp goes on all of them. There is no page range, no skip-the-cover option, no exclusions. Most of the time that is exactly right — a document is confidential or it is not, and a DRAFT that appears on page 1 and vanishes on page 2 is worse than useless.
When you genuinely need it on a subset, the workaround is to split the document at the boundary, watermark the piece that needs it, and merge the pieces back together. It is three tools instead of one, and the pages themselves come through perfectly — but be aware of what the round trip costs: split and merge rebuild the document by copying pages, and form fields, bookmarks and the Title and Author do not survive that. Watermarking alone keeps all of them; the workaround does not.
A watermark is not security
It marks a document; it does not stop anyone reading it. A password does that, and Protect PDF is the tool for it. Anyone who wants the stamp gone can get it gone, so treat a watermark as a label rather than a lock.
