Add a Watermark to a PDF
Stamp DRAFT, CONFIDENTIAL or any text across every page, choosing the size, angle, colour and how faint it sits. Runs in your browser with nothing uploaded.
Runs entirely in your browser — nothing is uploaded
Choosing the strength
This is the setting that decides whether the watermark works. Around 20 to 30 percent is the usual answer: dark enough to be unmistakable, light enough to read the page through. The default sits at 25.
The trap is going too faint. A mark at 5 percent looks elegant on screen and disappears entirely through a photocopier or a cheap office printer — and if the whole point was to stop a draft being mistaken for the final version, it has to survive the trip to paper. The tool says so when you drop below ten.
Diagonal or straight
Diagonal is the convention, and not only for looks: running corner to corner crosses more of the page, so the mark sits over body text wherever the layout puts it. Straight across suits short marks on documents with wide margins, where a diagonal would run off the edge.
Sideways pages are handled. A rotated page — a landscape table dropped into a portrait report — is stored one way and shown another, so a tool that ignores the difference puts the diagonal on the wrong diagonal. Each page’s own rotation is read and added to the angle, so every page carries the mark the same way.
It marks status, it does not protect anything
Worth being blunt about. A watermark tells a reader what they are holding: a draft, a copy, something confidential. It does not stop anyone doing anything. The text becomes ordinary page content, so someone with the right software can edit it out, and no watermark in history has prevented a page being photographed.
If you need a document that cannot be copied or altered, a watermark is the wrong tool and so is every free one on the internet. What this does well is remove ambiguity about which version is in someone’s hands.
Text rather than a logo
Only text, deliberately. Watermarks are overwhelmingly words — DRAFT, CONFIDENTIAL, a client name, a date — and keeping to text means there is no second file to add, no scaling decisions and no surprises about transparency. It also keeps the output small: the font used is Helvetica, one of the fourteen every PDF reader must provide, so nothing is embedded.
Nothing is uploaded
The document is opened, stamped and saved inside this tab. It matters here more than for most tools: the files people watermark are drafts, contracts and client work, which is exactly the category you should not be handing to a server you know nothing about in order to write one word across it.
Your original is untouched. The tool writes a new document, so the file on your disk stays as it was — useful, because the mark cannot be cleanly taken off afterwards.
Frequently asked questions
How faint should the watermark be?
Faint enough to read the page through it, strong enough to survive a photocopy. Around 20 to 30 percent is the usual answer for screen reading. Below about 10 percent it tends to disappear entirely once printed, which defeats the purpose — if the mark exists to stop a draft being mistaken for a final version, it has to survive the trip to paper.
Does it go over the text or under it?
Over. Slipping it underneath is possible and looks tidier, but any page with a filled background or a full-width image would hide it completely, and a watermark you cannot rely on seeing is worse than none at all. Lower the opacity rather than moving it behind.
What happens on sideways pages?
The mark stays centred and keeps the same angle you see on every other page. That is less obvious than it sounds: a rotated page is stored one way and displayed another, so a tool that ignores the difference puts the diagonal on the wrong diagonal, or off at an odd angle. The page’s own rotation is read and added in.
Can it be removed afterwards?
Not by any straightforward means, and that is rather the point — but do not mistake it for security. The text becomes ordinary page content, so someone determined enough can edit it out with the right software, and a watermark has never stopped anyone copying what is underneath it. It marks status; it does not protect anything.
Can I use my own logo instead of text?
Not here. Text is what the overwhelming majority of watermarks are — DRAFT, CONFIDENTIAL, a client name, a date — and keeping the tool to that means no upload step, no scaling decisions and no surprises about transparency. If you need a logo across every page, that is a job for a full PDF editor.