When to watermark a PDF
A watermark tells everyone who sees a document what it is and who it belongs to. Common uses:
- CONFIDENTIAL on HR, legal and financial documents.
- DRAFT on proposals and reports that are still being reviewed, so nobody mistakes them for the final version.
- COPY or SAMPLE on certificates, invoices and documents shared as examples.
- Your company or studio name on proofs, portfolios and quotations, to discourage reuse.
- “For [name] only” to personalise a document so leaks are traceable.
Layout options
- Once, centred – one large watermark across the middle of each page. The classic look for CONFIDENTIAL and DRAFT.
- Tiled across the page – the text repeats in a grid, covering the whole page. Harder to crop out; good for proofs and previews.
- Small, in the footer – a discreet line at the bottom of every page, such as “Confidential – Acme Ltd”. Ideal for internal documents that must stay readable.
Angle, size, opacity and colour
Angle: Diagonal (45°) is traditional and spans the page; Horizontal is cleaner; Diagonal (-45°) runs the other way; Vertical (90°) fits narrow margins.
Font size (pt): default 60 pt for a centred watermark. Tiled layouts look better at 30–40 pt; footers at 9–11 pt.
Opacity (%): default 18%. The watermark is drawn over the page, so lower values keep the content readable while still being obvious. For screen previews you want to protect, 30–40% is more forceful.
Colour: default red (#C0262D). Grey suits formal documents; brand colours suit proofs. Very light colours with low opacity can disappear when printed, so test-print important documents.
Step by step
- Add the PDF.
- Type the Text.
- Choose Layout, Angle, Font size, Opacity and Colour.
- Press Add watermark.
- Open the result and check it on a couple of pages.
The watermark is applied to every page, and each page’s own size and orientation is respected, so landscape pages in a portrait document are handled correctly.
Watermarks and security
A text watermark is a visible label, not encryption. It deters casual copying and makes the status of a document obvious, but someone with editing software could remove it. For sensitive documents, combine it with a password:
- Add the watermark here.
- Protect the result with Protect PDF, choosing Block editing and, if appropriate, Block copying.
Other finishing touches
- Number pages first with Add Page Numbers.
- Sign the document with Sign PDF – for a logo watermark, upload a transparent PNG there and place it on each page.
- Reduce the file size for email with Compress PDF.
- Turn a watermarked page into an image for social media with PDF to JPG.
Text and characters
Standard Latin letters, numbers and common punctuation are supported in watermark text. Very unusual symbols may be replaced, so keep watermarks simple – they work best as one to four words anyway.
Encrypted PDFs
If the PDF needs a password to open, unlock it first with Unlock PDF.
Privacy
Watermarking happens on your device. The document is never uploaded, which matters for exactly the kind of files people watermark – confidential ones.
Frequently asked questions
How do I add a watermark to a PDF for free?
Add the PDF, type your watermark text, choose layout, angle, size, opacity and colour, then press Add watermark. There is no watermark of ours added and no account needed.
Which opacity should I use?
15–25% keeps the text underneath readable. The default is 18%. Use 30–40% for a stronger deterrent on proofs and previews.
Can people remove the watermark?
A determined person with PDF editing software can remove or cover a text watermark. For stronger protection, also add a password with Protect PDF and block editing.
Can I add an image or logo watermark?
This tool adds text watermarks. For a logo, place a transparent PNG with the Upload option of Sign PDF on each page.
Does the watermark cover the text?
It is drawn over the page at the opacity you choose, so the content shows through. Lower the opacity if the document becomes hard to read.
Is my PDF uploaded?
No. The watermark is added in your browser with pdf-lib.