Add a watermark to a PDF
Stamp text like DRAFT or CONFIDENTIAL across every page, or overlay your own logo. Control opacity, angle, size, colour and whether it tiles. The document stays in your browser, which matters when the thing you are marking confidential actually is.
Add Watermark
text stamp · opacity, angle and tiling
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How to Add Watermark
- Add your PDF. Drag the file onto the drop zone. A live preview of the first page appears so you can see the watermark as you adjust it.
- Choose text or an image. Type the text you want, or upload a PNG logo. Transparent PNGs work best for image watermarks.
- Position and style it. Set opacity, rotation, font size and colour, choose a position on the page, and decide whether it should tile across the whole surface.
- Apply and download. Stamp every page or a selected range, then save the watermarked file.
Making a watermark that is visible but not annoying
The usual mistake is opacity. At full strength a watermark competes with the text underneath and makes the document genuinely hard to read; at 5% it is invisible when printed. Somewhere around 15-25% is the range where it reads clearly without obstructing anything.
Angle matters more than people expect. A watermark set at roughly 45 degrees crosses lines of text diagonally, so it is legible without ever sitting parallel to a line and being mistaken for content. Horizontal watermarks are easy to misread as part of the document.
For colour, mid-grey is a safer choice than red. It stays visible on screen and in print without dominating, and it photocopies sensibly. Bright red at low opacity often turns into a washed-out pink that looks like a printing fault.
A watermark is a deterrent, not a lock
It is worth being clear about what this does and does not achieve, because the two are often confused.
A watermark added this way is drawn into each page's content. It cannot be toggled off in a reader and it survives printing, screenshots and conversion to images. That makes it effective at what it is for: signalling status, discouraging casual reuse, and making it obvious if a draft escapes into the wild.
It is not a security control. Someone determined and technical can remove a watermark, particularly a text one on a mostly-white background. If you need the content itself protected, use Encrypt PDF to require a password, or Redact PDF to genuinely delete sensitive passages. If you need to know which recipient leaked a document, Fingerprint PDF is the right tool — it gives each copy a distinct invisible marker.
Why this one runs locally
There is a certain irony in uploading a document to a stranger's server in order to stamp the word CONFIDENTIAL on it. The files people watermark are, almost by definition, the ones they are being careful with — unreleased contracts, draft financials, pre-publication reports, client deliverables.
This tool applies the watermark in your browser. The document is never transmitted, so marking a file confidential does not require first making it slightly less so.
Frequently asked questions
Can the watermark be removed by whoever I send it to?
Not through any normal reader — it is drawn into the page content and survives printing and screenshots. A determined technical user could strip it, so treat it as a deterrent rather than protection. Use Encrypt PDF or Redact PDF if you need real security.
What opacity should I use?
Between 15% and 25% for most documents. Lower and it disappears in print; higher and it fights with the text underneath.
Can I use my company logo?
Yes. Upload a PNG — one with a transparent background gives much better results than a logo on a white rectangle, which will block whatever is behind it.
Are my files uploaded to a server?
No. The watermark is applied in your browser and the document never leaves your device, which matters given that watermarked files are usually the sensitive ones.
Can I watermark only some pages?
Yes. Specify a page range to stamp only those pages — useful when a cover page should stay clean.
Will the watermark appear when the file is printed?
Yes. It is part of the page content, so it prints exactly as it appears on screen.
Does adding a watermark increase the file size?
A text watermark adds almost nothing. An image watermark adds roughly the size of the image once, not once per page, since the same resource is reused across pages.
Can I put the watermark behind the page text instead of over it?
Not currently — the watermark is drawn over the page. In practice this matters less than it sounds: at 15-25% opacity the text underneath stays completely legible. Behind-content placement also does nothing on scanned pages, which have an opaque white background that would hide it entirely.