Add Watermark to PDF
100% private — runs on your device, never uploaded. Works offline once loaded.
Add a diagonal text watermark (like "CONFIDENTIAL" or "DRAFT") across every page of a PDF, with control over size, opacity and angle. Everything runs locally in your browser — a paid feature elsewhere, free and private here.
How a text watermark is applied
A watermark here is a rotated, semi-transparent block of text painted onto every page's content stream, typically at a diagonal angle so it doesn't obscure any single line of the underlying document while still being visible across the whole page. Opacity is handled through the PDF's transparency graphics state, which is why you can dial it down to something subtle like 10-15% for an internal draft, or push it to 40-50% when the goal is to make the page genuinely hard to reuse without attribution.
Because the text is rendered directly rather than embedded as an image, the watermark stays sharp at any zoom level and prints at whatever resolution the rest of the page prints at — there's no pixelation the way there would be with a low-resolution image stamp.
Common reasons people watermark a PDF
Freelancers and agencies watermark proofs and drafts ("DRAFT", "SAMPLE", "NOT FOR DISTRIBUTION") before sending them to a client, so if the file leaks or gets shared before the final invoice is paid, it's obvious it isn't the finished product. Legal and HR teams watermark documents with "CONFIDENTIAL" before circulating them beyond a small group, and companies distributing internal reports or leaked-sensitive financials often stamp each recipient's name or date across the page as a lightweight leak-tracing measure.
It's also common for photographers, designers and course creators selling PDF guides to stamp their brand name diagonally across preview pages, discouraging screenshots from being passed around while the paid, unwatermarked version stays exclusive to buyers.
Angle, size and opacity trade-offs
A 45-degree diagonal watermark covers more of the page diagonally than a horizontal one at the same font size, which is why it's the default convention for "CONFIDENTIAL" stamps — it's harder to crop out of a screenshot than text confined to one corner. Very high opacity combined with a large font size can make body text underneath genuinely hard to read on screen, which defeats the point if the document still needs to be usable, so it's worth previewing a page before committing to a batch of files with the same settings.
A quick tip
This applies the watermark to every page uniformly, so plan your workflow around that: keep an untouched master copy of the file somewhere, since the watermark becomes a permanent part of the page content and isn't something a viewer can toggle off afterward.
- Keep an unwatermarked master file — the stamp is permanent once applied.
- To exclude one page (like a signed final page), split the PDF first, watermark only the draft pages, then merge them back.
Frequently asked questions
Are my PDFs uploaded?
No — the watermark is drawn on your device and your file stays private.
Does it watermark every page?
Yes, the watermark is applied to all pages.
Can I control the color of the watermark text, or is it fixed?
Color, along with size, opacity and rotation angle, is adjustable before you generate the file, so you can match a lighter gray for subtle drafts or a bold red for stronger warnings.
Will the watermark print the same way it looks on screen?
Yes — because it's rendered as vector text with a transparency setting rather than a flattened image, what you see in the preview matches what comes out of a printer at the opacity you chose.
Does watermarking affect the file's text searchability or selectable text underneath?
No — the original text layer underneath the watermark is untouched and remains fully selectable and searchable; the watermark is simply painted on top as an additional layer.
Can someone remove the watermark from the PDF afterward?
A determined user with PDF editing tools could potentially remove a text watermark layer, so treat it as a deterrent and provenance marker rather than a hard security or DRM measure.
Is the watermark applied to every single page, including a cover page?
Yes, by default every page in the document gets the same watermark; if you need to exclude a specific page such as a cover or signature page, split it out beforehand and merge it back in afterward.
Can I add a diagonal watermark to a scanned PDF made of images?
Yes — the watermark text layer is added independently of whatever is already on the page, so it works the same whether the page is a scanned image or native text.
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