Watermark PDF
Stamp DRAFT, CONFIDENTIAL or any text across every page of a PDF.
About this tool
Load a PDF, type the stamp (or tap DRAFT / CONFIDENTIAL / COPY / SAMPLE), set opacity, size and colour, download. The text runs corner-to-corner across every page โ visible enough to state the document's status, light enough at the default 18% opacity to leave everything readable underneath.
What watermarks do and honestly don't
A watermark's real job is communication, not security: it makes the document's status travel with every copy, so a DRAFT can't be mistaken for final in a forwarded email chain, and a CONFIDENTIAL means nobody claims they didn't know. Be honest about the limit โ stamped text deters casual reuse and mislabelling, but a determined editor can remove it; genuine document security is access control, not ink. Craft notes: grey at low opacity is the professional register; red raises the temperature for DO NOT DISTRIBUTE; and the built-in PDF fonts cover Latin text only, which the tool checks before stamping rather than failing halfway. Watermark after merging so every page gets stamped, and see the image watermark tool for photos โ invoices usually want a PAID stamp, which is this tool with one word.
Frequently asked questions
Does a watermark protect my PDF?
It communicates, rather than protects: every copy visibly carries its status, which prevents honest mistakes and removes deniability. A determined editor can strip it โ real protection is controlling who gets the file.
What opacity should I use?
The 18% default keeps text readable under the stamp; 10% is a whisper for letterheads; 30%+ starts to shout and fight the content. Grey reads professional, red reads urgent.
Can I watermark in other languages?
Latin-alphabet text (including accents) works with the built-in PDF fonts. Other scripts and emoji would need embedded fonts, which this tool deliberately keeps out of scope โ it warns before stamping rather than producing boxes.
Is the file uploaded?
No โ stamping happens in your browser and the PDF never leaves your device. Free, no account, no page limits.