QuickMergeAdd a Watermark to a PDF
Short answer: To add a watermark to a PDF, enter the watermark text, choose its position and style, then download the finished file. QuickMerge adds the watermark in your browser without uploading the document.
Stamp a diagonal text watermark across every page — DRAFT, CONFIDENTIAL, a recipient name, or your own wording — with the size, opacity, colour and angle under your control. The whole thing runs in your browser, so a document you are marking as confidential is not uploaded to mark it.
How do I add a watermark to a PDF?
Drag & drop here
or click to browse
Mark Every Page — CONFIDENTIAL, DRAFT, or Your Own Text
A watermark tells everyone how a document should be treated before they read a word of it. This tool draws your text diagonally across every page at the size, colour, and opacity you choose — ideal for marking contracts CONFIDENTIAL, labelling revisions DRAFT, or adding your name to work you share.
The watermark is drawn as real PDF text on top of each page, so the original content is untouched underneath. Everything runs on your device via open-source browser libraries — your file is never uploaded. You can verify it yourself.
Next steps
Before this step
- combine the files first — so the watermark lands on every page of the final document.
Related tools
- remove a watermark instead — for marks that are still a separate layer, annotation or repeated text.
What to do with the result
- lock the watermarked file — so the mark cannot easily be removed.
- reduce the size after stamping — if the file grew.
Guides
- watermarking in Word and Excel — where most of this cluster’s demand actually is, and what survives an export to PDF.
- how to create a realistic rubber stamp — when you want a stamp mark rather than a diagonal watermark.
Browse all PDF tools, or see every QuickMerge tool.
Wondering how big a file this can take? We measured it: see Watermark PDF on the measured limits page, or the browser support matrix.
Frequently Asked Questions
Yes — type anything up to 40 characters (a name, a status like DRAFT, a company name). It is stamped diagonally across every page.
The watermark is semi-transparent (you control the opacity), so the underlying text stays readable. Lower the opacity for a subtle mark.
It is drawn into the downloaded copy. Your original file is never changed. For a truly tamper-resistant mark, flatten or protect the file afterwards.
No. The watermark is applied locally with pdf-lib; your document never leaves your device.
The watermark is applied across every page in one pass. To mark a subset, split out those pages, watermark them, then merge the document back together.
This tool stamps text — the wording, size, opacity, colour and angle are yours to set. For a logo or a rubber-stamp look, the stamp generator is the tool built for that.
It is drawn over the page at the opacity you choose. Lower the opacity or reduce the font size if body text becomes hard to read; preview the result before sending it on.
Yes, with the right software. A watermark marks status and ownership — it is not a security control. Use a password or redaction when the requirement is that something cannot be read.
Set the watermark text to the recipient name and produce one file per recipient. Because nothing is uploaded, generating several individually marked copies is quick and no version leaves your device.
Load the document, type the text you want, set the size, opacity, colour and angle, and download. Diagonal at 15-30% opacity is the setting that reads clearly without making the body text hard to follow — preview the result before sending it on.
Set the watermark text to DRAFT and apply it. A moderate opacity is right here: the point is that a reader notices the status immediately, not that the document becomes hard to read while it is still being reviewed.
This tool stamps text — you control the wording, size, opacity, colour and angle. For a logo or a rubber-stamp appearance, the stamp generator is the tool built for it.
That is a Word feature rather than a PDF one: Design → Watermark on Windows, or Insert → Watermark on the Mac, then pick a preset or choose Custom Watermark for your own wording. A Word watermark does survive an export to PDF, so if the finished file is going out as a PDF anyway, doing it in Word once is less work than doing it here afterwards.
No — it is processed in your browser. That matters here more than on most pages, since the documents people mark CONFIDENTIAL are exactly the ones that should not be passing through someone else's server on the way to being marked.
A watermark communicates status; it is not access control
“Confidential” or “Draft” can discourage casual redistribution, but it does not encrypt the PDF or prevent screenshots, printing or text extraction.
Write an unambiguous label
Use a status readers can act on: DRAFT, CLIENT COPY, CONFIDENTIAL or an expiry date. Avoid placing personal data in a watermark unless every recipient is authorised to see it. For individually tracked copies, include only identifiers your privacy policy permits.
Balance visibility and readability
A diagonal mark across the centre is difficult to crop away, but excessive opacity can obscure signatures and small print. Test the densest page in the document. Light grey often prints more reliably than a saturated colour on office printers.
Use the correct security layer
Add password protection when the file needs encryption in transit or at rest. Remove hidden metadata before external sharing. For regulated documents, use an approved document-management system with recipient access logs; a visual watermark alone does not establish who opened a file.
Security distinction reviewed 11 July 2026 · How QuickMerge publishes guidance
A watermark deters copying; it does not secure a document
Being straight about this matters, because the wrong assumption here has real consequences for anyone marking a confidential file.
A watermark can be removed
The text is drawn onto the page, and anyone determined enough can cover, crop or edit it out. Treat it as a clear statement of status and ownership — DRAFT, CONFIDENTIAL, a recipient name — rather than a control that prevents redistribution.
For actual confidentiality, combine tools
If the document must not be opened by the wrong person, add a password with real AES-256 encryption. If specific values must not be readable at all, redact them, which removes the underlying text rather than drawing over it. A watermark on its own does neither.
Legibility is the real design constraint
A watermark dark enough to deter reuse can make body text hard to read; one faint enough to ignore does not deter anyone. Diagonal placement at moderate opacity is the usual compromise, because it crosses the text column without sitting parallel to any line of it.
How to make a watermark on a PDF that reads without ruining the page
Applying one takes seconds. Getting it to deter reuse while leaving the document readable is the part that takes a second attempt.
Diagonal at moderate opacity is the working default
A watermark set across the page at roughly 45° crosses every line of body text instead of running parallel to one, which is what makes it hard to crop out or ignore. Opacity in the 15-30% range is the usual compromise: dark enough to read at a glance, light enough that the text underneath still scans. Above about 40% the document becomes tiring to read, and below 10% people stop noticing it at all.
DRAFT is a status; a name is a deterrent
A draft watermark on a PDF tells a reader not to act on the version in front of them, which is worth doing on anything circulating before approval. A recipient's name does something different: it makes a leaked copy traceable to whoever it was issued to, which changes behaviour in a way "CONFIDENTIAL" alone does not. Because nothing is uploaded, producing one individually marked file per recipient is quick and no version leaves your device.
Watermarking a subset of pages takes two more steps
The watermark is applied across the whole document in one pass. To mark only some pages — a confidential appendix, say — split those pages out, watermark them, and merge the document back together. Doing it in that order keeps the page sequence intact.
It marks the document; it does not protect it
Anyone with the right software can crop, cover or edit a watermark out. It is a clear statement of status and ownership, not a control. If the requirement is that the wrong person cannot open the file, add a password with AES-256 encryption. If specific values must not be readable, redact them, which removes the underlying text rather than drawing over it.