Watermark a PDF
A diagonal CONFIDENTIAL over a draft, a logo on every page of a proposal, or plain page numbers on a contract that arrived without them — one pass, whole folder.
- Runs entirely in your browser
- Works offline
- No upload
- No sign-up
- No watermark
Loading the tool…
How it works
- Drop your PDFs.
- Choose text, an image or page numbers, then position, size, colour and opacity.
- Apply — one file downloads directly, several come as a ZIP.
Why nothing is uploaded
Every operation on this page is done by code running inside your browser tab, using the same engine that renders web pages. The file is read from disk into your tab’s memory, transformed there, and written back out as a download. It is never sent anywhere — not to us, not to a third party.
Verify it yourself
- Open your browser’s developer tools (F12) and select the Network tab.
- Load your file and run the tool.
- The only requests you will see fetch the tool’s own code — and, for a few heavy tools, their open-source engine from a public CDN — plus one small page-view ping to loreatec.jp (page address and title, nothing more). None of them carry your file.
Frequently asked questions
Can the watermark be removed later?
By anyone with a PDF editor, yes — it is drawn on the page, not fused into the paper. A watermark deters casual reuse and marks a document’s status; it is not a security mechanism. For that, use the password tool.
Does Japanese text work?
Yes. The 14 fonts built into every PDF reader cover only Western letters, so Japanese (or any other script) is stamped as a high-resolution picture instead. It prints identically — it just is not selectable text.
How do the page numbers work?
Pick the page-numbers mode and a format like “{n} / {total}”. Each page gets its own number stamped as real text (not a picture), bottom-centre by default. It is the fix for a scanned or generated PDF that came without numbering.
Why is the default opacity so low?
Because a watermark that hides the text it sits on defeats the document. Around 20% reads clearly at arm’s length without making the page unreadable. Page numbers switch to full opacity automatically — those are meant to be read.