Why watermark a PDF without sending it to a server?

Watermarking is often done to protect a document before it's shared more widely — a draft, a licensed asset, a confidential proposal — which makes uploading it just to add the watermark somewhat self-defeating. NearPDF stamps the watermark locally, so the file only ever exists on your device.

How it works

1. Drop your PDF and type the watermark text — e.g. DRAFT, CONFIDENTIAL, or a recipient's name — into the box at the bottom of the workspace.
2. The box checks your text as you type and flags any characters the stamp can't draw (its built-in PDF font covers Latin-based scripts only).
3. Press Save. The text is stamped diagonally at 45° across every page, in semi-transparent gray, sized relative to each page so it stays visible without hiding the content.
4. Download the watermarked PDF.

Why the watermark is Latin-only (for now)

The stamp uses Helvetica, one of the standard fonts every PDF reader has built in — it costs zero download and renders everywhere, but it can only encode Latin-based characters (Western European letters, digits, common punctuation). Stamping Korean, Japanese, Chinese, Arabic, Thai or Cyrillic text would mean shipping font files weighing many megabytes, which sits badly with a tool whose whole point is that nothing is fetched or sent. So instead, the input box refuses what it can't draw and tells you which characters to change — before anything is processed. One honest caveat: a text watermark is labeling, not protection. It marks a draft as a draft and discourages casual reuse, but a determined person with a PDF editor can remove any watermark, from any tool.