Filebench
Files are processed on your device — nothing is uploaded
PDF · Stamping

Watermark a PDF

Mark a document as a draft, a copy or confidential. The text is drawn onto the pages themselves, so it survives printing and cannot be toggled off by the reader.

How to watermark a pdf

  1. Drop in a PDF.
  2. Type the text. CONFIDENTIAL, DRAFT and COPY are the usual ones; a client name or date works too.
  3. Choose a layout. Diagonal is the classic look and is hardest to crop out. Centred is more readable. The small footer option is for a discreet line along the bottom.
  4. Set opacity — around 20% sits behind the text without making it unreadable — then press Add watermark.

Why this one is different

Almost every free file tool works the same way: you upload your file to a company's server, their machine does the work, and you download the result. That means a copy of your document sat on someone else's hard drive, governed by a privacy policy you did not read.

Filebench does the work in the browser tab you are already looking at. There is no upload step because there is no server to upload to. The practical consequences: no file size limit, no queue, no account, no watermark, and it keeps working if your connection drops after the page loads.

FilebenchTypical online converter
Your file leaves your deviceNeverEvery time
File size limitNoneOften 10–100 MB free
Sign-up requiredNoUsually, past a few files
Watermark on outputNoSometimes
Works offline after loadingYesNo

Questions

Is the watermark permanent?

It is drawn into the page content, so it prints and it survives being copied. It is not an annotation that a reader can hide. It is not tamper-proof either — anyone determined enough with a PDF editor can remove drawn content. Treat it as a clear marking, not as security.

Can I watermark only some pages?

Yes. Put a range in the Pages box — 1-3, 7 — and only those pages are stamped. Leave it blank for the whole document.

Why is my long watermark running off the page?

Reduce the text size. The diagonal layout measures the text and centres it on the page, but a very long phrase at a large size will still exceed the diagonal. Around 60pt suits a single word on A4; drop to 30–40pt for a phrase.

Can I use an image or a logo as the watermark?

Not yet — this stamps text only. Image watermarking for PDFs is planned. For images rather than PDFs, the image watermark tool does the same job.

Does it work on scanned documents?

Yes. The watermark is drawn on top of whatever the page contains, so it works the same on a scan as on a text document.

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