Your files never leave this device — 100% in-browser

Watermark a PDF

A diagonal text stamp across every page — sized to the page, subtle enough to read through, applied on your device.

Type the watermark text (CONFIDENTIAL, DRAFT, a recipient name…), drop your PDF, and every page gets a diagonal semi-transparent stamp sized to fit the page. The document itself is untouched underneath — text stays selectable — and nothing is uploaded, which is rather the point of a confidentiality stamp.

Last verified 2026-08-15 — this tool passed 79 automated end-to-end checks

watermark text

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Drop a PDF here, or click to browse

converts to PDF · diagonal stamp on every page

01 — THE IRONY, SOLVED

Stamping "CONFIDENTIAL" on a document by uploading it to a random server defeats the word. Here the stamp is applied in your browser.

02 — SIZED TO THE PAGE

The stamp scales with each page's diagonal — consistent look across A4, letter and mixed-size documents.

03 — READ-THROUGH OPACITY

Light gray at 18% opacity marks every page without making the content beneath hard to read or print.

How to use

Drop your file(s) into the box above — or click it to browse.
Conversion starts immediately — no settings needed.
Click Download on each finished file — or Download all (.zip) for a batch. Nothing was uploaded at any point.

What a text watermark is actually for

Watermarks communicate status and provenance: DRAFT stops a work-in-progress being mistaken for final; CONFIDENTIAL reminds recipients of handling rules; a recipient's name ("For J. Kim — Mar 2026") discourages quiet re-sharing because every copy identifies its source. The stamp goes on every page, diagonally, sized to the page, in light gray that photocopies and prints visibly without obscuring content.

Honest limitations, stated plainly: this is a deterrent and a label, not security — a determined party can crop or rebuild pages. And v1 uses PDF's built-in fonts, which support Latin text only; Korean/Unicode watermarks need font embedding and are on the roadmap.

Stamp properties
Property	Value
Placement	Diagonal (45°), centered, every page
Sizing	Scaled to each page's diagonal
Style	Helvetica Bold, gray, 18% opacity
Text	Up to 60 characters, Latin (v1)
Underlying content	Untouched — text remains selectable

When NOT to watermark

As protection against copying — it deters and attributes; it does not prevent. For secrecy, control distribution instead.
Final signed contracts — altering an executed document can void its standing; watermark drafts, not executed originals.
Forms people must fill — heavy stamps over input fields make documents miserable to use.

Frequently asked questions

Can I use Korean text?

Not yet — PDF's standard fonts encode Latin only, and Unicode watermarks need an embedded font. It's on the roadmap; the image watermark tool handles Korean today.

Can the watermark be removed?

By a motivated person with tools, yes — that's true of every watermark. Treat it as labeling and attribution, not encryption.

Does it change my document's content?

No — the stamp is drawn as an additional layer; the original page content, text and links remain intact underneath.